Type material. Teresópolis, State of Rio de Janeiro, Brazil. P. Schirch Coll 1916. Each syntype was given an additional identification with a letter, A-C. MNRJ 216A: Body preserved in 80 % ethanol. MNRJ 216B: Body preserved in 80 % ethanol. MNRJ 216C: Three dimensional (3D) images and virtual sections were obtained by microcomputed tomography. Transverse sections of anterior extremity on 27 slides; horizontal sections of ovaries region on 39 slides; transverse sections of pre-pharyngeal region on 28 slides; sagittal sections of pharynx region on 111 slides and sagittal sections of copulatory apparatus region on 77 slides. Remaining part of body preserved in 80 % ethanol.

Species of Obama ~43–53 mm long; dorsal color traffic yellow, interspersed with pearl gold specks; esophagus 16 % of pharynx length; prostatic vesicle of inverted-J shape, with an intrabulbar portion; male atrium measuring 4 % of body length and twice as long as female atrium; penis papilla tapered, shorter than male atrium; female atrium funnel-shaped, 1.4 % body length.

Fixed, syntype C measured ~43 mm long, 7 mm wide and 1.6 mm high. Elongated body, with margins parallel; anterior end approximately rounded, posterior tapering (Fig. 1A). Dorsum convex, ventral side flat. Ground color of dorsum traffic yellow interspersed with pearl gold specks, thus resembling ocellated color of ocelot Leopardus pardalis. Ventral side lemon yellow (Fig. 1B).

The monolobate eyes are distributed on the anterior tip of the body, encircling the apex of the anterior tip. Posteriorly, the eyes spread onto the dorsum to occupy a band on either side of the body, with a maximum of 22 % of the body width, near region of the ovaries; towards posterior extremity they become less numerous. Sensory pits are simple invaginations 40 µm deep, located ventro-marginally in a single row that surrounds anterior extremity and continues posteriorly up to at least 13 mm of body length, as measured from anterior margin. Relative position mouth: body length, 56 %; relative position gonopore, 75 % in syntype C.

Figure 1. 

Obama itatiayana (Schirch 1929), syntype C A dorsal view B ventral view C original drawing by Schirch (1929).

Creeping sole comprising 93 % of body width. Abundant rhabditogen cells and glands producing erythrophil granules pierce dorsal and marginal epidermis; glands producing amorphous orangish-to-reddish secretion pierce marginal epidermis. Glandular margin is composed of glands producing erythrophil granules. Cutaneous musculature comprises three layers, viz., a subepithelial circular layer, followed by two diagonal layers with decussate fibers, and then a well-developed innermost layer of longitudinal muscles. Muscle fibers of longitudinal layer (45 µm thick dorsally; 75 µm thick ventrally) are arranged into bundles with 23–78 fibers each. Cutaneous musculature thickness relative to body height in pre-pharyngeal region, 10 % (Fig. 2A, C). Three parenchymal muscle layers, i.e. a dorsal layer of decussate diagonal fibers, a supraintestinal layer of transverse fibers, and a subintestinal layer with transverse fibers. Ventral nerve plate present (Fig. 2A, B).

Figure 2. 

Obama itatiayana (Schirch 1929). Syntype C A photomicrograph of a transverse section of pre-pharyngeal region B photomicrograph of horizontal section of ovarian region C photomicrograph of horizontal section of testicular region.

Mouth situated at a distance from root of pharynx equivalent to 40 % of pharyngeal pocket length. Pharynx bell-shaped. Esophagus 500 µm in length (Fig. 3A, B). Outer pharyngeal musculature consists of one-fiber-thick layer of longitudinal muscle, followed by a layer of circular muscle (15 µm thick) with longitudinal fibers interspersed. Inner pharynx musculature consisting of a subepithelial layer of circular fibers (50 µm thick) interspersed with longitudinal fibers.

Testes ~250 µm in diameter; the follicles are dorsally located between the dorsal parenchymal muscle layer and supraintestinal parenchymal layer (Fig. 2C). Anteriormost testes at a distance from the anterior extremity of the body equivalent to 11 % of body length; posteriormost testes are anterior to the pharynx, and at a distance equivalent to 46 % of body length. Efferent ducts run between the oviducts and dorsally to the nerve plate. Efferent ducts communicate with the latero-proximal region of the prostatic vesicle (Fig. 3C). Prostatic vesicle divided into an anterior, extrabulbar half running dorsally, and a posterior, intrabulbar half having the shape of an inverted J (Fig. 3A). Anterior half of prostatic vesicle with folded wall and lined by a 50 µm high columnar ciliated epithelium which is pierced by glands producing erythrophil granules. Intrabulbar half of vesicle lined with a 30 µm high epithelium; this intrabulbar half pierced by glands producing erythrophil granules being more intensely stained than those in the anterior half. Prostatic vesicle surrounded by a 50 µm thick layer of muscle fibers variously oriented, mainly, diagonal and circular. Prostatic vesicle continues as ejaculatory duct within the penis papilla. This duct curves ventrally to open at the tip of the penis papilla. Ejaculatory duct lined with an erythrophil, 5 µm high ciliated epithelium and surrounded by a circular muscle layer (12 µm thick). Penis papilla conical, with dorsal insertion shifted posteriorly and lined with an 80 µm high columnar epithelium, which is pierced by glands producing erythrophil granules. This epithelium is surrounded by a 100 µm thick coat of muscles consisting of interlaced circular and longitudinal fibers (Fig. 3C).

Male atrium 1.7 mm long (4 % of body length), not folded, partially occupied by the penis papilla. Male atrium lined with a 15 µm high non-folded columnar epithelium, which is pierced by the openings of abundant glands producing erythrophil granules (Fig. 3A, C). Male atrium covered by a 12 µm thick layer of circular and diagonal muscle fibers, best visible in its ventral region.

Ovaries ovoid, ~400 µm in maximum length, situated above the ventral nerve plate (Fig. 2B), situated at a distance from anterior extremity equivalent to 30 % of the body length. Ovovitelline ducts emerge from the lateral portion of the ovaries. Anterior to the gonopore region, the oviducts curve dorso-medially and, subsequently, join to form a common glandular ovovitelline duct, the latter located dorsally to the female atrium (Fig. 3C). Shell glands pierce the distal portion of the ovovitelline ducts. Common glandular ovovitelline duct 300 µm long and running ventrally to enter the female genital canal. Common ovovitelline duct and female genital canal lined by a ciliated epithelium, which is surrounded by a 10 µm thick layer of circular muscle (Fig. 3A, C).

Female atrium 750 µm long, funnel-shaped, with its posterio-dorsal portion receiving the female genital canal. Female atrium lined with a 50–400 µm high epithelium; this epithelium presents a stratified aspect and its free surface is indented (Fig. 3A, C). Female atrial epithelium is pierced by the openings of abundant glands, producing erythrophil granules, and surrounded by a weak muscle layer of circular fibers that is contiguous with that on the common muscle coat. Male atrium: female atrium ratio, 2:1.

Common muscle coat consists of interwoven circular and longitudinal muscle fibers enveloping the unpaired portion of the prostatic vesicle, male and female atria, and part of the common glandular ovovitelline duct.

Figure 3. 

Obama itatiayana (Schirch 1929). Syntype C A µCT-derived image. Virtual sagittal section of pharynx and copulatory region, pixel size: 6.3 µm B photomicrograph of sagittal section of pharynx C photomicrograph of sagittal section of copulatory apparatus.

Municipality of Teresópolis (-22.42, -43.01) and Itatiaia (-22.41, -44.65), State of Rio de Janeiro, Brazil.

The three syntypes A, B, C, and individuals studied by Riester (1938) are very similar to each other in their external aspect. Syntype C and Riester’s specimens are also similar in their internal organs, namely the shape of the pharynx and the copulatory apparatus.

Riester (1938) redescribed the species from additional specimens. Froehlich (1955b) synonymized Geoplana duca Marcus, 1951, from São Paulo and Mogi das Cruzes (state of São Paulo) with G. itatiayana. However, body color and details of the male and female atria of G. duca do not match those of O. itatiayana. In this regard, we disagree with Froehlich’s taxonomic action. A revision of the taxonomic status of G. duca is, therefore, desirable.

A fourth putative type specimen of O. itatiayana, viz., specimen MNRJ 8906, does not conform to the original description as its body is narrower, the dorsum more convex and has a pearl orange midstripe and a pair of paramedian pale brown stripes, external to which the color is beige gray (Fig. 4A). The pharynx and copulatory apparatus of this specimen (Fig. 4B), as revealed from µCT-derived virtual sections, resemble O. itatiayana, but the specimen is incompletely mature. The vial of this specimen also contains a label reading “Geoplana itatiayanensis”, as well as another reading “G. itatiayana”. We suspect that at some point during curatorial handling this individual was mislabeled and confounded with the types of O. itatiayana.

Figure 4. 

Specimen MNRJ 8906 mislabeled as O. itatiayana A in dorsal view B virtual sagittal section of pharynx and incipient copulatory apparatus, pixel size: 10 µm.

MNRJ 210, holotype, here designated by monotypy: Teresópolis, State of Rio de Janeiro, Brazil. P. Schirch (unknown year). Preserved in 80 % ethanol. Three dimensional (3D) images and virtual sections were obtained by microcomputed tomography.

Species of Paraba 25 mm long; dorsal side yellowish green ground color with a narrow median black band; long and narrow prostatic vesicle, inverted ‘U’-shape; male atrium with 6–8 transverse annular folds; ovovitelline ducts ascend anterior to gonopore; female atrium lined with an epithelium that protrudes into male atrium.

Fixed holotype 25 mm long; body with greatest width in the pharyngeal region, 5 mm. Towards the extremities, the body narrows gently, with the anterior tip being rounded and the posterior end being obtuse (Fig. 5A, C). Dorsal side strongly convex; ventral side flat. Dorsum ochre brown, with irregular areas of cream color as a result of fading (Fig. 5A, D). Body margins in anterior 1/6 of the body with beige color. Ventral side ochre yellow (Fig. 5C).

A single row of eyes contours the anterior first millimeter of the body (Fig. 5E); posteriorly they extend for ca. 4 mm, arranged in a row with 2–4 eyes on either side of the body. Further posterior, eyes could not be discerned. Sensory pits are simple invaginations located ventro-marginally in a single row from the very anterior body tip to at least 2 mm posteriorly (Fig. 6A, E). Relative position mouth: body length, 66 %. Relative position gonopore: body length, 82 %.

Figure 5. 

Paraba bresslaui (Schirch 1929), holotype A dorsal view B original drawing by Schirch (1929) C ventral view D dorsal view with original label E anterior extremity.

Figure 6. 

Paraba bresslaui (Schirch 1929), µCT-derived images of cephalic extremity of holotype A, B perspective view of 3D rendering C virtual transverse section showing anteriormost eyes, pixel size: 1.9 µm D virtual transverse section showing eye and sensory pit, pixel size: 1.9 µm E horizontal virtual section showing rows of sensory pits, pixel size: 1.9 µm.

Two-millimeter long paired cerebral ganglia, commencing 5 mm posterior to anterior extremity. Ventral nerve plate present (Fig. 7A). Longitudinal cutaneous musculature well developed, with fibers gathered in bundles (Fig. 7A, D). Cutaneous musculature thickness relative to body height at the pre-pharyngeal region, ~4 %. Cephalic retractor muscle absent.

Mouth opening at the posterior section of the pharyngeal pouch. Pharynx cylindrical (Fig. 7B, C), with a dorsal insertion slightly posterior to the ventral one. Short esophagus present. Testes rounded, the largest follicles ca. 200 µm in diameter. They are located dorsally and are arranged in a row of ca. 20 follicles on either side of the body (Fig. 7D), each row having up to two testes in the same transverse plane. Most anterior testes are located dorsally to the ovaries and 1 mm posterior to the cerebral ganglia, i.e., at a distance from anterior extremity equivalent to 32 % of the body length; posterior-most testes shortly anterior to the pharyngeal root.

Figure 7. 

Paraba bresslaui (Schirch 1929), holotype. µCT-derived images and diagrammatic reconstruction A virtual transverse section of pre-pharyngeal region, pixel size: 7.99 µm B diagrammatic reconstruction of sagittal sections of pharynx C virtual horizontal section of testicular region, pixel size: 7.99 µm D virtual horizontal section of copulatory region, showing tangential section of ventral cutaneous muscle fibers, pixel size: 4.5 µm. Asterisk indicates artifact.

Lateral to the prostatic vesicle, the sperm ducts recurve and then open into a branch of the prostatic vesicle (Fig. 8D). Prostatic vesicle with an inverted ‘U’-shape in lateral view (Fig. 8C), with its ascending portion having a sinuous wall, while the descending portion is straight. At its distal most portion, this vesicle bends posteriorly to penetrate the antero-ventral region of the penis bulb. Prostatic vesicle surrounded by a 100 µm thick distinct mass, presumably consisting of muscles and glands. This vesicle is located at anterior portion of the penis bulb, the latter extending 1 mm anterior to the penis papilla.

Inside the penis bulb, the prostatic vesicle communicates with the ejaculatory duct. This duct is horizontally positioned and runs through the penis papilla to open at its tip. Penis papilla cylindrical, with the distal portion truncated in lateral view (Figs 8A, B, 9A, B), but conical in dorsal view (Fig. 9A). It fills 2/3^rd of the male atrium length. Male atrium broad, with 6–8 transverse, annular folds. Anterior-most fold is the largest and surrounds the basis of the penis papilla. Length of male atrium twice of that of the female atrium.

Ovaries 230 µm in diameter and approximately rounded. They are positioned at 8 mm from anterior extremity of the body, and 1 mm posterior to the cerebral ganglia. They are located above the ventral nerve plate (Fig. 7D). Ovovitelline ducts emerge from the dorso-lateral aspect of the ovaries (Fig. 7A) and run posteriorly horizontally to the level of the gonopore. Then they ascend obliquely to the sagittal plane and join the common glandular ovovitelline duct immediately above the posterior region of the female atrium. Common glandular ovovitelline duct (~100 µm long) runs ventrally to join the female genital canal, the latter being a ~160 µm projection of the posterio-dorsal region of the female atrium. Female atrium ~1 mm in length and 0.5 mm in height, equivalent of 1/4 of the body height. This female atrium is elongate and is lined with an epithelium with a very high epithelium (~250 µm), typical of epithelia with a stratified aspect, which occupies the whole cavity except for an irregular narrow canal (Fig. 9A, B). This female lining epithelium presents a cone-shaped protrusion into the male atrium. The gonopore canal is vertical and 500 µm long.

Figure 8. 

Paraba bresslaui (Schirch 1929), holotype A diagrammatic reconstruction of copulatory apparatus B virtual sagittal section of copulatory apparatus, pixel size: 4.5 µm C virtual sagittal section showing prostatic vesicle, pixel size: 1.9 µm D virtual transverse section of body showing prostatic vesicle, pixel size: 1.9 µm.

Figure 9. 

Paraba bresslaui (Schirch 1929), holotype A virtual horizontal section of copulatory apparatus, pixel size: 7.99 µm B virtual sagittal section of copulatory apparatus, pixel size: 7.99 µm C horizontal section of ovarian region, pixel size: 7.99 µm.

Municipality of Teresópolis (-22.42, -43.01), State of Rio de Janeiro, Brazil.

The general shape and size of the body agrees with the original description (“length 25 mm; maximum width 8–9 m[m]” (Schirch 1929) and correct labeling of the specimen as the holotype by monotypy is assumed (Fig. 5B). Fading of the body color is normal, especially after 90 years of conservation in a preservative.

The specimen has the characteristics of the subfamily Geoplaninae, albeit the width of the creeping sole could not be ascertained. We assume a wide creeping sole on the basis of the flat ventral side of the specimen.

Further features observed on this species match only one genus of the Geoplaninae, namely Paraba Carbayo et al., 2013, whose diagnosis reads: “Geoplaninae with small-to-medium-sized body, 6–80 mm in length; body slender, with margins nearly parallel; dorsum and ventral side slightly convex; eyes monolobulated; pharynx cylindrical; prostatic vesicle extrabulbar, generally horizontal; penis papilla protrusible, conical; male atrium not folded; ascending portion of ovovitelline ducts lateral to the gonopore canal or to female atrium, joining each other above female atrium; genital canal dorso-anteriorly flexed, arising from the posterior-dorsal region of female atrium; female atrium rounded, clothed with an epithelium with multilayered aspect” (Carbayo et al. 2013: 523). In view of the internal morphology of the species, herein presented for the first time, it is justifiable to transfer the species to Paraba.

This species only differs from the diagnostic features of Paraba in some details that deserve a comment: (a) the dorsum is not slightly, but strongly convex, (b) the male atrium is not unfolded, but folded, and (c) the female atrium is not rounded, but elongate. These differences probably represent artefacts or intrageneric variation: the two former features (shape of the dorsum and folds of the male atrium) might have been caused by contraction during fixation or, simply, the male atrium is folded. An elongate female atrium is also found in other species of Paraba (namely Pa. franciscana, Pa. rubidolineata).

Regarding the external aspect, Pa. bresslaui differs from all other congeneric species in the color pattern, consisting of a yellowish green ground color, ornamented with a median black stripe, and beige pigment spots, often elongated and parallel to the main body axis. None of the 14 species of Paraba present a green-yellowish dorsal color with a median black stripe and beige spots stretching longitudinally, as in Pa. bresslaui.

Regarding the internal aspect, there are four species resembling Pa. bresslaui in having a U-shaped prostatic vesicle, namely Pa. cassula (E. M. Froehlich, 1955a), Pa. goettei (Schirch, 1929), Pa. phocaica (Marcus, 1951) and Pa. piriana (Almeida & Carbayo, 2012, in Almeida et al. 2012). However, Pa. phocaica is the only species sharing with Ps. bresslaui the posterior insertion of the genital canal into the female atrium. Both species also share distinct features: an annular fold around the basis of the penis papilla, a male atrium folded, and the general shape of the prostatic vesicle. Apart from body color, however, Pa. bresslaui is distinguished from Pa. phocaica in that the latter species presents a more dorsal entrance of the prostatic vesicle into the penis bulb (vs. ventral as in Pa. bresslaui), a rounded female atrium (vs. elongate), and a lining epithelium of the female atrium not invading the male atrium (vs. invading it).

Type material. Four syntypes collected by P. Schirch Coll (year unknown) in Teresópolis, State of Rio de Janeiro, Brazil. We received them on loan in 70 % ethanol with only a label reading 8915. Each syntype was given an additional identification with a letter, A–D. Three dimensional (3D) images and virtual sections of syntype MNRJ 220A were obtained by microcomputed tomography. Parts of the bodies of syntypes were histologically sectioned as follows. Syntype MNRJ 220A: Transverse sections of posterior extremity on 14 slides; remaining part of body preserved in 80 % ethanol. Syntype MNRJ 220B: Sagittal sections of copulatory apparatus on 156 slides; remaining part of body preserved in 80 % ethanol. Syntype MNRJ 220C: Horizontal sections of anterior extremity on 31 slides; horizontal sections of ovaries on 71 slides; transverse sections of pre-pharyngeal region on 35 slides; sagittal sections of pharynx on 94 slides; sagittal sections of copulatory apparatus on 124 slides; remaining part of body preserved in 80 % ethanol. Syntype MNRJ 220D: Preserved in 80 % ethanol.

Additional material examined: Specimen MZUSP PL XXXX, studied by E. M. Froehlich (1955a): Teresópolis, Parque Nacional da Serra dos Órgãos, State of Rio de Janeiro, Brazil (geographic coordinates not available), E. M. Froehlich et al., leg. 1953. Transverse sections of pre-pharyngeal region on two slides (S761-S762); sagittal sections of pharynx on one slide (S763); sagittal sections of copulatory apparatus on ten slides (S764-S773). F6484 (MZUSP PL XXXX): Parque Estadual da Pedra Branca, Rio de Janeiro, State of Rio de Janeiro, Brazil, -22.933, -43.447, Carbayo et al., leg. 9 Dec. 2014. Sagittal sections of copulatory apparatus on 101 slides; remaining part of body preserved in 80 % ethanol.

Species of Pasipha 60–70 mm long; dorsum with black brown dots on ivory ground color; eyes dorsal, occupying lateral band on each side of body, 44 % of body width; posteriormost testes between pharynx and copulatory apparatus; prostatic vesicle inverted U-shaped in lateral view, not bifurcated; ovovitelline ducts emerge from inner-dorsal side of ovaries; male atrium folded; length of male atrium to female atrium ratio, 8:1; female atrium as long as high.

Living adult (F6484) 70 mm in length and 10 mm wide. Fixed adults (F6484 and syntype C) 65–71 mm long, 6 mm wide, and 1.7 mm high. Elongated body, with margins approximately parallel; anterior and posterior extremities rounded. Dorsum slightly convex, ventral side flat. Ground color of the dorsum of living animals is ivory, richly ornamented with black brown dots (Fig. 10A, B, D, E). Towards the body margins, these dots tend to anastomose into longitudinal striae. Striae are lacking in a thin medial stripe which is bordered on each side by an irregular line of the same color as the dots. Ventral side is sulfur yellow, with the anterior extremity light ivory and the pharyngeal region zinc yellow (Fig. 10C). After 89 years or more in a preservative, the dorsal color of the four syntypes has turned ochre yellow and the dots faded to a terra brown color (Fig. 10D, E); their ventral body surface has become olive yellow.

Monolobate eyes surround the anterior extremity of the body (Fig. 11A). They also spread onto the entire dorsum except for a thin median line ~8 % of the body width (Fig. 11B). Towards the posterior extremity, they become scarcer. Sensory pits are simple invaginations 25 µm deep, located ventro-marginally in a single row from the very anterior body tip up to at least 57 % of the body length (syntype C). Relative position of the mouth 69 % of body length, that of the gonopore 90 % in syntype C (68 %, and 91 %, in specimen F6484).

Figure 10. 

Pasipha plana (Schirch 1929) A live specimen F6484 in dorsal view B original drawing by Schirch (1929) C ventral view of live specimen F6484 D set of all syntypes with anterior extremity to right E syntype B fixed in dorsal view.

Figure 11. 

Pasipha plana (Schirch 1929), specimen F6484 in clove oil A dorsal anterior extremity B dorsal mid-body region.

Creeping sole comprising 96 % body width. Abundant rhabditogen cells and glands producing erythrophil granules pierce dorsal and marginal epidermis; glands producing amorphous orangish-to-reddish secretion pierce marginal epidermis. Ventral epithelium is pierced by glands producing fine erythrophil granules. Glandular margin absent. Cutaneous musculature comprises three layers, namely a subepithelial circular layer, followed by a double diagonal layer with decussate fibers, and then a well-developed, innermost longitudinal layer (Fig. 12A, B). Muscle fibers of the longitudinal layer (120 µm thick dorsally; 88 µm thick ventrally) are arranged into bundles with 30–50 fibers each. Cutaneous musculature thickness relative to body height at the pre-pharyngeal region, 13 %. Three parenchymal muscle layers present, all well-developed: dorsal layer of decussate diagonal fibers (60 µm thick), supraintestinal layer of transverse fibers (100 µm thick), and subintestinal layer with transverse fibers (65 µm thick; Fig. 12A, B). Ventral nerve plate present.

Mouth situated at a distance from the root of the pharynx equivalent to 50 % of the pharyngeal pocket length. Pharynx collar-shaped (Fig. 12C), with dorsal insertion very close to the end of the pharyngeal pocket. Esophagus absent. Outer pharyngeal musculature difficult to discern; apparently it consists of a one-fiber-thick subepithelial muscle layer (6 µm thick) of longitudinal fibers followed by an equally thick layer of circular fibers. Inner pharynx musculature consisting of a subepithelial layer of circular fibers (80 µm) in the anterior region of the pharynx; this circular layer is followed by scattered longitudinal fibers in the posterior region of the pharynx (syntype C).

Figure 12. 

Pasipha plana (Schirch 1929) A specimen F6484 photomicrograph of a horizontal section of ovaries region B F6484 photomicrograph of transverse section of pre-pharyngeal region C syntype A virtual section of a sagittal section of pharynx, pixel size: 12 µm.

Testes are ~300 µm in diameter and dorsally located between the supraintestinal parenchymal muscle layer and intestine. Anteriormost testes at a distance from the anterior extremity of the body equivalent to 29 % of body length; posteriormost testes are posterior to the pharynx, close to the prostatic vesicle, and at a distance equivalent to 85 % of the body length (syntype C).

Sperm ducts contain sperm in their distal region; a 60 µm thick circular muscle surrounds the distal region of these ducts. Sperm ducts run between the oviducts and onto the nerve plate. Lateral to the prostatic vesicle, efferent ducts curve forward and medially to communicate with the latero-proximal region of the prostatic vesicle (Fig. 13A).

Prostatic vesicle extrabulbar, long and narrow, divided into an anterior half running dorsally, and a posterior half, running ventrally, so describing an inverted U-course. Initial portion of prostatic vesicle with folded wall and lined by a 12–30 µm high cuboidal-to-columnar ciliated epithelium which is pierced by abundant glands producing erythrophil (purple) granules (Fig. 13B, C). Distal half lined with a 3 µm high epithelium that becomes 10 µm high in the section communicating with ejaculatory duct. This distal half pierced by numerous glands producing erythrophil (reddish) granules. Prostatic vesicle surrounded by variously oriented muscle fibers. This muscle is 200–400 µm thick around the proximal region, and thinner and less dense around distal region. Entire prostatic vesicle and its musculature are enveloped by a thin coat of muscle fibers, which are readily discerned from that of the common muscle coat.

Figure 13. 

Pasipha plana (Schirch 1929) A specimen F6484 diagrammatic reconstruction of copulatory apparatus B photomicrograph of prostatic vesicle, ejaculatory duct, and male atrium in sagittal section C photomicrograph of distal portion of prostatic vesicle and of ejaculatory duct in sagittal section.

Prostatic vesicle penetrates the ventral aspect of the common muscle coat and is continuous with the ejaculatory duct. This duct recurves dorsally before bending abruptly posteriorly to open into the anterior region of the male atrium (Fig. 13C). Ejaculatory duct lined with a cyanophil, 10–12 µm high, ciliated epithelium, and is surrounded by a circular muscle (10–15 µm thick) of thin fibers (1 µm in diameter).

Male atrium a 5 mm long cavity (syntype C, 8 % of body length) with large folds along its dorso-anterior 3/4. Posterior quarter is large but with smaller folds. Male atrium lined with an 8–15 µm high epithelium, ciliated along the anterior 3/4 of its length, and with its free surface papillate (Fig. 15). This epithelium is pierced by glands producing erythrophil (reddish-to-purple) granules and which are abundant throughout the entire epithelium, with the exception of that lining the sphincter (Fig. 14A, see below), which is pierced by abundant glands producing erythrophil (reddish) granules, especially in its ventral region (Fig. 14B).

Subepithelial musculature of male atrium consists of a 12 µm thick layer of circular and longitudinal muscle fibers, which sometimes intermingle and sometimes are arranged in two layers. This muscle continues with very abundant longitudinal and circular fibers located in the surrounding space delimited by the common muscle coat. A well-developed sphincter of circular muscle embraces the subterminal region of the male atrium. Dorsal region of the sphincter is posterior to the ventral (Fig. 14A, B).

Ovaries ovoid-shaped, 500 µm in maximum length, and situated immediately above the ventral nerve plate (Fig. 12A). They are at a distance from the anterior extremity equivalent to 22 % of the body length (syntype C). Ovovitelline ducts emerge from the inner-dorsal region of the ovaries. Posterior to the gonopore region, they curve medially and dorsally then join to form the common glandular ovovitelline duct, posteriorly to the female atrium. There are no shell glands discharging their secretion into the ovovitelline ducts (Fig. 13A). Common glandular ovovitelline duct 120 µm long (syntype C) and runs dorsally to enter the female genital canal. This canal (800 µm long in syntype C) is a projection of the posterio-dorsal region of the female atrium, and runs posteriorly and ventrally. Common ovovitelline duct and female genital canal are lined by a ciliated epithelium which is surrounded by a 25 µm thick muscle comprising fine (~1 µm) circular and diagonal fibers.

Female atrium short and ample, roughly as long as high. Its posterior wall projects anteriorly, giving it a square shape. Epithelial lining 12–25 µm high. Female atrial epithelium pierced by glands producing erythrophil granules and surrounded by a muscle layer of longitudinal and circular fibers in some regions, and deccussate in others. Male atrium: female atrium ratio, 8:1.

Common muscle coat is comprised of interwoven circular and longitudinal muscle fibers. It is less developed in its posterior region and envelopes the male and female atria and the common glandular ovovitelline duct (Figs 13A, 15).

Figure 14. 

Pasipha plana (Schirch 1929). Specimen F6484 A virtual sagittal section of copulatory apparatus, pixel size: 12 µm B photomicrograph of sagittal section of copulatory apparatus.

Figure 15. 

Pasipha plana (Schirch 1929). Syntype A virtual sagittal section of copulatory apparatus, pixel size: 12 µm.

Areas covered with Atlantic forest in the municipalities of Teresópolis (-22.42, -43.01) and Rio de Janeiro (-22.93, -43.44), State of Rio de Janeiro, Brazil.

Schirch (1929) described only the external appearance of this species. Froehlich collected one specimen in the type locality and described its external and internal morphology (E. Froehlich 1955a). By comparing her specimen with the succinct original description, she considered that they are conspecific (E. Froehlich 1955a). Indeed, apart from the external aspect, the internal morphology of Froehlich’s specimen matches in all aspects that of the syntypes, especially the copulatory apparatus of syntypes A, B, and C, herein described for the first time. This similarity also applies to the specimen F6484, recently collected by us. Thus, it is safe to assume that the syntypes, Froehlich’s specimen and specimen F6484 are all conspecific.

Currently, the species is placed in Pasipha Ogren & Kawakatsu, 1990. The diagnosis of this genus was revised by Carbayo et al. (2013). Pasipha comprises 24 species (plus five5 species considered incertae sedis, see Carbayo et al. 2013). Regarding the external aspect, Pasipha plana can be distinguished from all congeners in that it displays dark dots which anastomose into longitudinal striae.

Regarding the internal aspect, Pa. plana shares only with Pa. cafusa (Froehlich, 1956), Pa. chimbeva (E. M. Froehlich, 1955a), Pa. oliveiroi (Froehlich, 1955b), Pa. pasipha (Marcus, 1951), Pa. penhana (Riester, 1938), Pa. pinima (E. M. Froehlich, 1955a), Pa. rosea (E. M. Froehlich, 1955a), Pa. splendida (Graff, 1899), Pa. tapetilla (Marcus, 1951) and Pa. velutina (Riester, 1938) a non-branched prostatic vesicle. However, among these eleven species, only in Pa. rosea, Pa. tapetilla and Pa. velutina is the length of the male atrium to the female atrium ratio > 3:1, as in Ps. plana. In Ps. plana, however, this ratio is as high as 8:1. Furthermore, differing from Ps. plana, in Pa. rosea the prostatic vesicle is more sinuous and elongate, and the length of the female atrium is twice that of its height (vs. roughly as long as high in Pa. plana); in Pa. tapetilla, there is a barrel-shaped and muscular copulatory organ (vs. absent in Pa. plana). Finally, in Pa. velutina there is a penis papilla-like annular fold in the proximal region of the male atrium (vs. absent in Pa. plana).

Type material. Two syntypes available, collected by P. Schirch in 1917 at Baixo Guandu (former Maylasky), State of Espírito Santo, Brazil. We received them on loan in 70 % ethanol with label reading 8914. Three dimensional (3D) images and virtual sections of syntype MNRJ 206A were obtained by microcomputed tomography. Parts of body of syntype MNRJ 8914B were histologically sectioned as follows. Syntype MNRJ 207B: Transverse sections of anterior extremity on 20 slides; horizontal sections of a region posterior to anterior extremity, 4.5 mm long on 73 slides; transverse sections of pre-pharygeal region on 50 slides; sagittal sections of pharynx on 135 slides; remaining part of body preserved in 80 % ethanol.

Syntype 206 is 160 mm long, 10 mm wide, and ~2 mm high (Fig. 16A, C); syntype 207, 70 mm, ~8 mm, and ~2 mm (Fig. 16D), respectively. Elongated body, with margins approximately parallel; anterior extremity pointed, posterior rounded, body sides rounded. Dorsum convex, ventral side flat, convex on some portions of median region most probably the result of contraction at moment of fixation. Ground color of dorsum clay brown with irregular faded areas visible to naked eye (Fig. 16A, D). Ventral side grey beige.

Eyes monobolate, surround anterior extremity of the body (Fig. 17A) and are distributed evenly dorsolaterally along the entire body length. Sensory pits are simple invaginations 15 µm deep, located ventro-marginally in a single row (Fig. 17B) that contours the anterior extremity and extends posteriorly at least ~4 mm (or 7 % of the body length). Relative position of the mouth: body length, ~55 %. Relative position of incipient gonopore: body length, ~70 % in syntype 207.

Figure 16. 

Pseudogeoplana arpi (Schirch 1929) A fixed syntype A in dorsal view B original illustration of G. arpi by Schirch (1929) C virtual µCT reconstruction of body of Syntype A D dorsal view of syntype B.

Figure 17. 

Pseudogeoplana arpi (Schirch 1929), photomicrographs of syntype B A transverse section of anterior extremity B transverse section of pre-pharyngeal region C transverse section of anterior extremity D horizontal section of testicular region.

Epithelium ciliated in anterior extremity, dorsally and ventrally; otherwise only ciliated on the ventral surface. Creeping sole comprising 92 % body width. In pre-pharyngeal region, abundant rhabditogen cells and glands producing erythrophil granules pierce dorsal and marginal epidermis; glands producing amorphous orangish-to-reddish secretion pierce marginal and dorsal epidermis. Ventral epithelium pierced by glands producing fine erythrophil granules. Glandular margin absent (Fig. 17C).

Cutaneous musculature comprises three layers, namely a subepithelial circular layer, followed by a diagonal layer of decussate fibers, and then a well-developed innermost longitudinal layer. Muscle fibers of the longitudinal layer (45 µm thick dorsally; 75 µm thick ventrally) arranged into bundles with 13–46 fibers each. Cutaneous musculature thickness relative to body height in the pre-pharyngeal region, 10 % (Fig. 17C). No muscle modifications in anterior extremity (Fig. 17A, B). Three parenchymal muscle layers present: a dorsal layer (10 µm thick) of decussate fibers, a supraintestinal layer (100 µm thick) with transverse fibers, and a poorly developed subintestinal layer (100 µm thick) of transverse fibers (Fig. 17D). Ventral nerve plate well developed.

Mouth situated at a distance from the root of the pharynx equivalent to 32 %-47 % of pharyngeal pocket length (syntypes 206 and 207, respectively). Pharynx cylindrical, tending to bell-shaped (Fig. 18A, B), occupying anterior half of the pharyngeal pocket. Esophagus absent. Free surface of outer pharyngeal epithelium undulated and ciliated, underlain by a subepithelial longitudinal muscle (8 µm thick) and followed by a circular muscle (50 µm thick). Inner pharyngeal musculature consisting of a subepithelial circular muscle (25 µm thick), followed by a longitudinal muscle (5 µm).

Testes poorly developed, rounded, ~100 µm in diameter, with no developed sperm. They are dorsally located among fibers of the supraintestinal transverse parenchymal muscle layer. Anteriormost testes at a distance from the anterior extremity of the body equivalent to 26 % of body length; posteriormost testes, 36 %, i.e., anterior to pharyngeal pocket (Fig. 17D).

Copulatory apparatus very poorly developed (Fig. 18C, D). It occupies the ventral 2/3^rd of the body height. Each of the paired sperm ducts opens into the proximal region of the bifurcate prostatic vesicle. This vesicle is intrabulbar and consists of an unpaired region running ventro-posteriorly inside a weakly developed penis bulb. Prostatic vesicle opens into a flat cavity, 35 µm high and 250 µm wide, delimited by a dorsal fold and a ventral fold. These folds project posteriorly from the anterior wall of the male atrium, forming a structure resembling a short, conical penis papilla. Ejaculatory duct not observed. Male atrium forms a 1.5 mm long closed cavity, i.e., it does not open to the outside of the body through an eventual gonopore canal. The atrium is narrower posteriorly and there is no differentiation between the male and female atria. The atrial epithelium is a mass of tissue, the limit of which is diffuse. Poor quality of the histological sections did not permit the description of additional details (Fig. 18C).

Figure 18. 

Pseudogeoplana arpi (Schirch 1929) A syntype A virtual sagittal section of pharynx, pixel size: 10 µm B syntype B diagrammatic reconstruction of sagittal sections of pharynx C syntype B photomicrograph of sagittal section of incipient copulatory apparatus D syntype B reconstruction of incipient copulatory apparatus.

This species presents all the characteristics of the subfamily Geoplaninae, i.e., creeping sole covering most of the ventral surface, mouth posterior to the midbody, a well-developed cutaneous musculature organized into bundles, part of the parenchymal muscle layers organized in longitudinal fibers, and dorsal testes (see Almeida et al. 2019).

Since the syntypes present only poorly developed copulatory organs, it is not possible to allocate the species to any other genus. Consequently, the species should remain in Pseudogeoplana.

We received only one specimen identified as Pseudogeoplana blaseri. This specimen exhibits an aspect different from that of the original description. The external aspect was illustrated by Schirch (1929) (Fig. 19). In Schirch’s collection, no specimen resembles the original description of Ps. blaseri. A mislabeling must have happened prior to deposition or during the curation of the material. Thus, the holotype of Ps. blaseri should be considered lost. Nonetheless, we studied this available mislabeled specimen and provide further evidence of mislabeling (see “Dolichoplana sp.” in the following section).

Figure 19. 

Original illustration of G. blaseri by Schirch (1929).