Illustrated type catalogue of Amphidromus Albers, 1850 in the Natural History Museum, London, and descriptions of two new species

Abstract The collection of the Southeast Asian tree snail genus Amphidromus Albers, 1850 at the Natural History Museum, London includes more than 100 lots of type specimens representing 85 name-bearing types, 9 paratypes and 6 paralectotypes, and one nomen nudum. Lectotypes are here designated for Amphidromus cambojiensis, Amphidromus perakensis globosus, Amphidromus columellaris gloriosa, Amphidromus maculiferus inflata, Amphidromus lepidus, Amphidromus sinistralis lutea, Amphidromus moniliferus, Amphidromus maculiferus obscura, Amphidromus sinistralis rosea and Amphidromus sinensi vicaria. In addition, the missing types of A.A. Gould were discovered and their type status is discussed. A complete catalogue of these types, including colour photographs is provided for the first time. After examining these type specimens, two new Amphidromus species, Amphidromus (Syndromus) globonevilli Sutcharit & Panha, sp. n. and Amphidromus (Syndromus) principalis Sutcharit & Panha, sp. n. were recognized and are described herein.


Introduction
Amphidromus Albers, 1850 is a genus of tree dwelling snails; the members of this genus are distributed in the region from Assam in India throughout Indochina, the southern of the Philippines, Indonesia (east of Weber's line) with a single species occurring in the Northern Territory of Australia (Pilsbry 1900, Solem 1959, 1983, Laidlaw and Solem 1961, Sutcharit and Panha 2006. This diverse genus of large snails with colorful shells has long been known to malacologists. The first revision of Amphidromus by Fulton (1896a) arranged nominal species into 19 species groups, and included descriptions of new species with illustrations. Pilsbry's revision (1900) provided more complete descriptions and redescriptions and figured species, some for the first time, becoming the standard identification guide for the group. Laidlaw and Solem (1961) gathered and documented further information on previously recognised species and provided a list of all species-group names applied to Amphidromus. The most significant issue of Laidlaw and Solem (1961) was the recording of the primary type specimens, the institution where they were deposited and registration number for all the species within the entire genus. More than 300 nominal species-group names have been applied to this genus (Richardson 1985), but only 75 were recognized as distinct species in Laidlaw and Solem (1961), since then an additional 16 species have been describied and validated (see Solem 1983, Dharma 1993, Panha 1996, Lehmann and Maassen 2004, Severns 2006, Sutcharit and Panha 2006b, 2011, Chan and Tan 2010, Cilia 2013. This indicates that Amphidromus are morphologically variable, especially in shell colour, which has led to an over-description of some taxa, and species recognition based solely on published descriptions and figures are being difficult. Therefore, type specimens are the ultimate reference point for species identification, and represent an international standard providing the basis of nomenclatural stability when following the International Code of Zoological Nomenclature (ICZN). Comparison with the primary type specimens will minimise this difficulty, at least within the constraints of morphological taxonomy.
The Natural History Museum in London (hereafter the NHM), formerly the British Museum (Natural History), is one of the oldest and largest museum collections with mollusc specimens acquired from many varied sources and collectors (Dance 1986). Two collections that contain important type material of the genus Amphidromus are those of Hugh Cuming (containing 27 type specimens of Amphidromus described by L. Pfeiffer and L. Reeve) and Hugh Fulton (included 60 type specimens of Amphidromus). These two collections were deposited at the NHM and form the largest collection of primary type specimens of Amphidromus, being comprised of 87 taxa (~one-fourth of the currently known Amphidromus taxa). Until now, many of these types have not been figured or adequately figured (Laidlaw and Solem 1961). The second largest collection of Amphidromus type material is in the Senckenberg Forschungsinstitut und Naturmuseum in Frankfurt (51 taxa), where all the specimen lots have been catalogued and illustrated (Zilch 1953). Thirty-three type lots of Amphidromus are housed in the National Museum of Natural History, Smithsonian Institution the remaining type lots are distributed amongst other museums. However, the primary types of 57 taxa had not previously been traced (Laidlaw and Solem 1961). Some of these 'missing' lots have subsequently been traced such as those located at the National Museum of Wales, Cardiff (Wood and Gallichan 2008).
Recent research on Amphidromus systematics including detailed morphological studies of reproductive anatomy and molecular phylogenetics (Sutcharit et al. 2007) needs to be integrated with a critical assessment of type material. This will allow for the correct application of nomenclature and the recognition of suitable voucher specimens that can act as surrogates of type specimens for DNA and additional morphological work, since historical species were often described based solely on shells. The aim of this paper is to evaluate the type status of Amphidromus type specimens in the NHM collections and to figure specimens and designate lectotypes in acordence with ICZN (1999: Art. 74) guidelines. Evaluating species as biological entities is largely outside of the scope of this study. However, examination of these type collections, revealed two Amphidromus species that we consider to be new and these are described herein.

Materials and methods
Collections: The primary type specimens (i.e. holotype, lectotype and syntype/syntypes) along with the paratype(s) and paralectotype(s) of Amphidromus described from the early 19 th century until 2013 and deposited at the NHM were examined. Those specimens that were confirmed as forming part of the type series of species, where a unique type had not been designated, were considered to be syntype lots. In cases where a holotype was not explicitly designated but where in the original publication the species name was clearly based on an individual shell, these were taken to be the holotype fixed by monotypy. Lectotypes mentioned in this catalogue have been designated by Laidlaw and Solem (1961), unless otherwise stated, and conform to the ICZN guidelines (1999).
From the published list of Gould's type specimens, Johnson (1964) presumed that some of the unlocated types were probably to be found in the NHM. Although, most of A. Gould's types can be found in the Museum of Comparative Zoology, Harvard University, there was a record that Gould presented the specimens of some species that he had described to Hugh Cuming (Johnson 1964). Among Gould's types that were unequivocally recognized in the NHM, the original labels are obviously marked with "Type" and their locality is congruent with the recorded type locality. For example, Johnson (1964: 88) certainly accepted the type specimen of "Anodonta horda Gould, 1855" was in the H. Cuming collection and designated a specimen (NHMUK registration no. 196465) as the lectotype (Fig. 1A). Such evidence is, therefore, taken into account in order to distinguish Gould's type specimens.  Gould, 1855, lectotype (NHMUK 196465) designated by Johnson (1964: 88). The original label marked with "Type" does not frequently occur in H. Cuming's collection, which suggests that the specimen was received from Gould B Label of A. atricallosus (Gould, 1843), the printed label attached on the top is typical of the way that Reeve used to indicate the specimen examined and figured in the Conchologica Iconica C Label of A. bataviae (Grateloup, 1840) D Label of A. bulowi Fruhstorfer, 1905E Label of A. cruentatus (Morelet, 1875) F Label of A. hosei Smith, 1895. This illustrated catalogue provides the shell measurements and photographs of the name-bearing types. All specimens considered as forming part of the type series were photographed in the standard position, apertural and abapertural views. Additional views were also photographed for the taxa that have unique shell characters. The original labels were photographed and checked with the original description (Figs 1, 2). Measurements of any holotype and lectotype material were taken in mm with digital calipers. Those taxa where the primary type is housed in a different institution to the NHM, but where paratypes or paralectotypes are kept in the NHM, are also included in this illustrated catalogue.
Structure of the illustrated catalogue: The taxa in this illustrated type catalogue were checked against the original publications and are listed as given in the original description regardless of termination or incorrect original spelling, and the authorship(s) and date. Additional comments, such as the print date, availability of the name or corrected subsequent spelling, are provided in square brackets. The synonymy tabulation and the usage of each taxon name are provided in Pilsbry (1900), Laidlaw and Solem (1961) and Richardson (1985). Only the original combination of the taxon name with reference to pages, plate and/or figures are mentioned. The type locality is given verbatim as stated in the original publication. If possible, the modern name and/or regional names of the type locality are provided in square brackets. If any incongruence between the published type locality and that given on the original label occurred, this is mentioned in the comments under the remarks of those taxa. Under the type materials, primary type specimens with the NMH registration number (registered specimens are cited as NHMUK), the measurements of shell height (H) and shell width (W), and the figures are given. In addition, if the paratypes or paralectotypes of that taxa are available then the respective registration number, number of specimens with a dextral (D) or sinistral (S) coiling direction, and figures of a representative specimen are given. If necessary, remarks are given on the status of type specimens, authorships, availability of name, notes on the type locality, and other necessary comments. Full bibliographic references are provided at the end of this paper.
Institutional abbreviation: Abbreviations of the museum collections used the lists of taxa and species descriptions are listed as follows:  (Gould, 1856), with Pfeiffer's handwritten "sinensis Bens. var." B Bottom of a box with A. adamsii luteofasciata type specimens. The two larger glued labels are Fulton's original handwritten ones. On the right side, the vertical lines indicate an unambiguously designated lectotype in Laidlaw and Solem (1961) with reference to Fulton's (1896) original figures C Label of A. masoni (Godwin-Austen, 1876), with Godwin-Austen's handwritten the species and locality names D Label of A. melanomma (Pfeiffer, 1852), with Pfeiffer's handwritten of the specie name in blue ink E Label of A. moniliferus (Gould, 1846), the name "theobaldianus, Reeve -from type" was subsequently added up later F Label of A. andamanicus nicobarica Godwin-Austen, 1895.
Remarks.  described "abbasi" in the Occasional Molluscan Papers which does not fulfill the ICZN guidelines and could not be made available  (ICZN 1999: Arts 8.6 and 11.1). However, "abbasi" was later published correctly (ICZN 1999: Art. 8) and made available in Chan and Tan (2010).
The authors stated that three specimens were housed in the NHM under this paratype lot, but only two are registered in the NHM collections (Chan and Tan 2010 Fig. 3C).
Remarks. There is a variation in the spelling of the species name, of which "adamsi" is considered as an incorrect subsequent spelling. References of the subsequent use of the incorrect spelling have been compiled in Laidlaw and Solem (1961: 597). The original and correct spelling is "adamsii".
Remarks. Fulton wrote "Boettger, MSS." after the species name, but it appears that there was no description by O. Boettger. The taxon is, therefore, attributed solely to Fulton.

Amphidromus angulatus Fulton, 1896
Amphidromus angulatus Fulton, 1896a: 84, 85, pl. 6, fig. 3 Remarks. Gould (1844: 457) mentioned that two specimens were the basis for the species description, but did not explicitly designate a holotype. Johnson (1964: 44) stated that "figured holotype MCZ 169050", but this specimen does not match with the original figure, especially in the differing location of the dark varix (Gould 1844: pl. 24, fig. 3). The holotype that Johnson specified seems to be inappropriate, and should be interpreted as a lectotype designation (ICZN 1999: Art. 74.6) to stabilise the name. In addition, the "paratype FMNH 72403" mentioned in Sutcharit and Panha (2006b: 14) is misinterpreted. This specimen from the Laidlaw ex. Fulton collection from the type locality should be considered as a topotype.
The dextral specimen, from the H. Cuming collection and figured in Reeve (1848), has an original label stating "type" and the locality is congruent with the type locality (Fig. 1B). This supports that supposition that the specimen likely came from Gould's type series and is, therefore, considered as the paralectotype. In addition, Johnson (1964: 88) recognized a sinistral specimen as "paratype MCZ 169051". However, if this sinistral specimen originated from the original type series, Gould would have most likely mentioned the sinistral specimen in the original description and is in the opionion of the authors unlikely to be type material.
Type locality. North Borneo.
Remarks. The original description does not include an illustration, however Morlet (1889: 177, 178, pl. 6, fig. 4) re-published the description and included illustrations of the species. Fischer-Piette (1950: 158) cited a specimen in the Muséum National ďHistoire Naturelle, Paris collections as the "holotype, 25 mm" which we consider an inadvertent lectotype designation (ICZN 1999: Art. 74.5). The NHM specimen is from the H. Fulton collection ex. Dautzenberg and ex. Morlet and gives "Cambodia" as the collection locality. It is considered to be a paralectotype.
Remarks. Bulimus cambojiensis Reeve, 1860 was described from a specimen collected by H. Mouhot. When describing Bulimus cambojiensis, Reeve did not designate a unique type. Fulton (1896a) figured this species for the first time, but did not clearly state their syntype status. The specimen that most closely matches the original description (Reeve 1860: 204) and the figure in Fulton (1896a: pl. 7, fig. 7) is designated here as the lectotype to stabilise the name.
Variation in the spelling of the species name is found as "cambodjensis" or "cambogiensis", but both are considered as incorrect subsequent spellings (Morelet 1875: 260, Pfeiffer 1877: 23). The correct original spelling "cambojiensis" is here highlighted to be maintained as proper usage.

Amphidromus chloris Reeve, 1848
Bulimus chloris Reeve, 1848 Remarks. The locality on the original label of the type series states the sample was collected from the Philippine Islands. The type locality is, therefore, confined to the Philippines Islands. This is congruent with the known distribution of this species from the Mindanao and Sulu archipelagoes of the Philippines (Bartsch 1917).

Amphidromus concinna Fulton, 1896
Amphidromus pictus var. concinna Fulton, 1896a: 85, pl. 5, fig. 9 Remarks. Fulton stated in the original description that the type series were from two localities. The specimen figured in the original description was designated as the lectotype by Laidlaw and Solem (1961: 611). As a result the type locality of this taxon is restricted to "South Flores Island, East Nusa Tenggara, Indonesia", the locality of the lectotype.
Remarks. The original description was based on more than one specimen and three sets of measurements were given. The unique type was not explicitly designated, and the single specimen that remained in Fulton's collection could not be implied to be the unique type (ICZN 1999: Art. 74.6). The "holotype" referred to in Laidlaw and Solem (1961) is explicit with a unique indication that constitutes a valid lectotype designation. Therefore, this specimen should be recognized as the lectotype to stabilise the name.
Remarks. The type locality in the original description was given as Palawan. However, the locality on the label of the lectotype is Balabac Island, the southernmost of the Palawan Islands.

Amphidromus floresianus Fulton, 1897
Amphidromus floresianus Fulton, 1897: 211, pl Remarks. The name "globosa", an unavailable name, was included in this catalog in order to indicate the history of the taxon. This name was introduced without a description or indication and therefore failed to conform to the ICZN guidelines (1999: Art. 12) and could not be made available by Nevill (1878). Later, this name was cited in Pilsbry (1900: 191) and Richardson (1985: 44). They cited this name without vaidating the taxon, and so this name could not be made available in subsequent works (ICZN 1999: Arts 11.5.2, 12).
We have surveyed for Amphidromus in western Thailand and collected a number of specimens with similar shell morphology to Nevill's (1878) original specimen. It appear to be an undescribed species, therefore, we provide a species description and description of genitalia anatomy as Amphidromus (Syndromus) globonevilli Sutcharit and Panha, sp. n. (see description below).
Remarks. This species was described based on specimens from Annandale and Robinson's collection in the Malay Peninsula. Laidlaw and Solem (1961: 622) stated "… the location of the material is unknown." We located seven specimens in the NHM general collections with an original label stating that they were purchased from Annandale and Robinson, with the locality "Biserat State of Jalor, Malay Peninsula". We consider these specimens to be the syntypes. The specimen that most closely matches the original description is here designated as the lectotype.
Regarding the authorship of this name, Collinge (1903: 211, 212) clearly stated that H. Fulton provided him with the brief definition and the species name. Fulton, therefore is solely attributed the authorship (ICZN 1999: Art. 50.1.1).
Remarks. Authorship was originally attributed to O. Boettger from a manuscript name. However, since O. Boettger did not write the description, the taxon is attributed to Fulton only. The brief original description clearly implied that it was based on more than one specimen. However, no illustration or measurements were provided, and the unique type was not designated in the original publication. Two specimens from NHM collection accompanied with Fulton's handwritten label stating the taxon name and collection locality are considered to be syntypes. The specimen that most closely matches with the description is here designated as the lectotype to stabilise the name.
The specimens that Pfeiffer used as the basis for "Bulimus maculiferus var. β.", were examined and used by Fulton, and are acknowledged as the type series (ICZN 1999: Art 72.4). A single specimen in the NHM from H. Cuming' s collection with Fulton's handwritten labels bearing the taxon name and the locality "Mindanao, Philippines" is considered to be a possible syntype. This specimen corresponds closely with the figure in Küster and Pfeiffer (1854: pl. 40, fig. 9). However, the specimen is much smaller in size than the specimens quoted in Pfeiffer (1853: 319). Therefore, we treat the NHM specimen as a possible syntype.
Remarks. Fulton wrote "Bttg. MSS." after the variety name, but did not appear to give O. Boettger credit for the description. Therefore, authorship is attributed to Fulton.
Remarks. Three specimens originally from the Fulton collection with his handwritten label bearing the taxon and the type locality were located in the NHM collections. The largest shell (64.2 × 34.2 mm) clearly corresponds to the original description and Fulton's measurements (66 × 38 mm) and so is here designated as the lectotype to stabilise the name.
Remarks. The type locality "New Hebrides" seems to be an error, since this is beyond the known range of Amphidromus. Subsequent collections and reports confine the species distribution to Burma from the Tavoy and Mergui archipelagos (Nevill 1878, Pilsbry 1900, Gude 1914, Laidlaw and Solem 1961.

Amphidromus lepidus (Gould, 1856)
Bulimus lepidus Gould, 1856: 12. Remarks. Johnson (1964: 28, 29) indicated that some of the unlocated specimens from Gould's type catalogue were probably in the NHM, since Gould presented some specimens to H. Cuming. No speceimens of Bulimus lepidus Gould, 1856 could be located by Johnson (1964: 100). There is a specimen in the NHM from the H. Cuming collection marked with "Type" and the locality "Mergui Islands" (Fig. 2A) which corresponds to the type locality, and the shell matches the measurements given in the original description (height 22.5 mm, width 12.5 mm). In addition, Fulton (1896a: 80) stated that "the type" of Bulimus lepidus is in the British Museum (now the NHM). This specimen is, therefore, considered as the syntype, and is here designated as the lectotype to stabilise the name. It is figured here for the first time since it was described.
Remarks. Fulton (1896a: 85) described the type as being bleached in condition, and suggested that the specimen should have a color pattern if it were not bleached. We examined the lectotype but, in contrast, consider it to be entirely white in shell colour and not bleached. In addition, Laidlaw and Solem (1961) suggested that Amphidromus quadrasi Hidalgo, 1887 and Amphidromus versicolor Fulton, 1896 from the Philippines were probably junior synomyms of this species. With a unique straight columella, thickened parietal callus and elongated aperture, Amphidromus lindstedti (Pfeiffer, 1857) is clearly distinct from both speceis. However, new collections from precise localities will help elucidate whether this is a distinct species or a colour form of the other taxa.   Fig. 10F).
Remarks. The original description gave the type locality as "unknown". However, the original label accompanying the lectotype states it was collected from Java. The type locality of this taxa is, therefore, confined to Java.
Remarks. Fulton (1896a) correctly nominated this name, but attributed the authorship to von Martens. However, von Martens (1867: 355) described the subspecific name as 'B' which is an invalid (ICZN 1999: Art. 11.9). Therefore, the authorship of this taxon should be attributed to Fulton.
The original description was very brief, without any measurements or illustrations, and did not indicate that a unique type was designated. The NHM holds a lot with eight shells from the Da Costa collection, with the original label stating "Fulton co-types" which are considered syntypes. The specimen that has a small label with Fulton's handwritten glued inside the aperture is designated here as the lectotype to stabilise the name. The paralectotypes are the other seven specimens from the same lot.

Amphidromus masoni (Godwin-Austen, 1876)
Bulimus masoni Godwin-Austen, 1876: 316. Remarks. Godwin-Austen (1876) stated that there were two specimens in the type series. Only a single specimen from the Godwin-Austen type lot remains in the NHM collections (Fig. 2C). Laidlaw and Solem (1961: 639) considered this specimen to be the holotype. This should be interpreted as an inadvertant lectotype designation (ICZN 1999: Art. 74.6). The apex of the lectotype has been damaged at around the second and third whorls and the shell height is much smaller than it would have been if undamaged.
The NHM holds a lot that has an original label in Pfeiffer's handwriting giving the species name (in blue ink) and the collection locality of "Malacca". The words "B. melanoma var γ Pfr. Mon. Hel. III p. 310", not written by Pfeiffer, were added to the label at a later time (Fig. 2D). The specimen illustrated in Küster and Pfeiffer (1854: pl. 39, figs 27, 28) is recognized by the sinistral shell, with a yellow peripheral band on the periphery of the last whorl and the dimensions are very close to those given in the original description. Since the lot contains two other dextral specimens which were not mentioned in the original description, we refrain from designating this as a lectotype,  considering the sinistral specimen to be a possible syntype. The other two dextral shells (NHMUK 20140753/2-3) that are contained in the lot are excluded from the type series (ICZN 1999: Art. 72.4.1).
Remarks. Gould noted that he received several specimens (dextral and sinistral) from F. Mason, and he wrote his original description from the sinistral specimen (Gould 1846). However, in the catalogue of Gould's type specimens, Johnson (1964) could not locate any type material of Bulimus moniliferus. A single specimen was found in the NHM from the H. Cuming collection with "Type" written on it and the locality "Tavoy" which corresponds to the type locality in the original description (Fig. 2E). In addition, F. Mason, the original collector who presented specimens to Gould, mentioned that local people (Karen ladies) often strung the shells of A. atricallosus and others congeners from their necklaces (Mason 1850: 400). Evidence of a hole remains on the basal lip of the lectotype of Bulimus atricallosus (MCZ 169050) and in the NHM type specimen of Bulimus moniliferus Gould, 1846. This specimen is, therefore, designated as the lectotype to stabilise the name.
Remarks. Godwin-Austen clearly stated that this taxon was described based on only one specimen. Therefore a single specimen ex. Röepstorff (Fig. 2F) in the NHM collections is recognized as the holotype fixed by monotypy (ICZN 1999: Art. 73.1.2).
Remarks. The original description was based on more than one specimen, since Fulton stated "…remarkable that this is the only form of maculiferus of which dextral specimens have been found…". A unique type was not indicated in the original description. The NHM holds a lot that consists of three specimens (2D, 1S) from the H. Cuming collection with an original label in Fulton's handwriting. The dextral specimen closely matches with the original description and is here designated as the lectotype to stabilise the name.
Remarks. The specimen from Fulton's collection with an accompanied label bearing a handwritten taxon and locality is considered to be a syntype (ICZN 1999: Art. 72.4). However, in the original description, Fulton provided the measurements of an adult specimen, yet only a juvenile specimen was located in the NHM.
Remarks. The original description was very brief and H. Rolle never designated a unique name-bearing type. Later, Zilch (1953) designated the lectotype from H. Rolle's collection in the Senckenberg Museum. The NHM registration records show that a specimen was purchased from Sowerby and Fulton's collection with the original label stating "Co-type" and giving the locality "Roma I.". Therefore, we consider this specimen to be a paralectotype.

Remarks. Fulton attributed the authorship to von Martens. However, von
The NHM holds a lot with Fulton's handwritten labels bearing the taxon and type locality. The specimen that corresponds most closely with the original description is designated as the lectotype.
Remarks. Möllendorff (1894) provided a very brief definition of the taxon without figures. The type locality as written on the lectotype label was "Tschaya". The NMH possess a lot of two shells purchased from H. Rolle, which are considered to be probable paralectotypes.
Remarks.  described "rottiensis" in the Occasional Molluscan Papers which does not fulfil the ICZN (1999: Art. 8.6) guidelines, and could not be made available (ICZN 1999: Art. 11.1). However, the same species name was later published correctly (ICZN 1999: Art. 8) and made available in Chan and Tan (2010).
Remarks. There are two specimens from H. Cuming's collection accompanied with Fulton's handwritten label stating the taxon name. The type locality in the original publication was given as N. Borneo, but this lot has no locality. However, these specimens closely match the original description, especially in colour pattern and so it seems likely that these were indeed the shells that Fulton based the species description upon. Therefore, on this basis, we consider these specimens to be probable syntypes.
Remarks. The lectotype was designated from H. Rolle's collection (Zilch 1953: 133, pl. 23, fig. 20). The NHM holds one lot of 2 specimens from the type series, labeled as "co-type", and these are considered paralectotypes.
Remarks. Fulton attributed the authorship of this variety to von Martens (1867: 357). However, von Martens only describe this varietal form with a letter "Bulimus adamsii var. D.", which is not a valid name (ICZN 1999: Art. 11.9). Later "subunicolor" was appropriately described and figured in Fulton (1896a). The basal lip or bottom of the aperture of the lectotype was damaged and so the shell height given here is much smaller than the actual specimen size.
Remarks. The original description seems to be based on one specimen and a single set of measurements was given. Benson (1857: 329) stated "peristomate tenui?" [=peristome thin?], and Theobald (1876: 187) also stated "…described by Benson from an imperfect example", which we have interpreted as meaning that the type specimen is an immature shell. The NHM holds a lot containing a juvenile specimen figured in Hanley and Theobald (1870: pl. 19, fig. 10), and the label states "from Hanley coll. figd in Con. Ind. pl. 19, fig. 10". The collection locality states "Tenasserim" which agrees with the original description. However, this specimen is larger than the dimensions given, so we refrain from designating it as the lectotype.
Remarks. Möllendorff indicated that the specimens examined in the original description were from H. Fruhstorfer's collection. The lectotype was designated by Zilch (1953: 133) and is housed in the Senckenberg Museum. The NHM registration records show that the two specimens were purchased from H. Fruhstorfer. The specimen locality is "Annam" which matches with the type locality. We therefore consider these specimens to be paralectotypes. Remarks. Fulton clearly stated in the original description that the type series was composed of two lots from Pegu, and Chittagong. No specimens from Chittagong were located in the NHM collections. However, the specimen that most closely matched with the original description in Fulton (1896a: 80) and is figured in Hanley and Theobald (1876: pl. 21, fig. 5) is designated here as the lectotype, NHMUK 1888.12.4.975. The type locality of these taxa is here restricted to "Pegu", the locality of the lectotype.

Amphidromus webbi Fulton, 1907
Amphidromus webbi Fulton, 1907: 152-153, pl. 9, fig. 8 Diagnosis. This new species can be distinguished from A. sinensis (Benson, 1851) by having a smaller, more ovate conic shell (Fig. 16G-I). It differs from A. flavus (Pfeiffer, 1861) which exhibits an elongated conic shell a faint yellowish spiral band below the periphery, and an elongated aperture (Fig. 7I, J). It differs from A. lepidus (Gould, 1856) and A. roemeri  by having a yellowish shell colour with two dark brown spiral bands below the periphery, while A. roemeri have a more ovate to stout shell, whitish in colour with reddish-brown spiral bands below the periphery (Fig. 13E, F) and A. lepidus has a monochrome whitish shell (Fig. 10C).
Description. Shell. Shell small, sinistral, ovate conic, rather thin; umbilicus perforate. Apex acute without black spot; spire short; suture depressed and wide. Whorls slightly convex; last whorl round to ovate. Periostracum thin and transparent. Shell colour yellowish, paler near apex; subsutural band white and with darker yellow band below. Last whorl with two brown spiral bands below periphery. Aperture wide and ovate; columella straight; lip white and little expanded; parietal callus thin and transparent.
Internal wall of penis almost smooth surfaced, corrugated into a series of thickened; proximal to genital orifice, with swollen longitudinal penial pilasters (pp). Penial verge (pv) large, elongated conical shape, about two-thirds of penis length and with smooth surface (Fig. 17B). Vagina (v) cylindrical, longer than penis, held in position with series of thin muscles originating from foot floor. Vaginal pouch and stimulator pilaster absent. Gametolytic duct (gd) long, slender; proximal to genital orifice enlarged same diameter as vagina, and distal to genital orifice tapering to small tube connected to gametolytic sac (gs). Oviduct (ov) and albumen gland (ag) enlarged; hermaphroditic gland (hg) multilobed and connected with hermaphroditic duct (hd) (Fig. 17A).
Internally, vaginal wall sculptured with longitudinal vaginal pilasters (vp); proximal to genital orifice with smooth and continuous ridges about two-third of its length, and pilasters at distal to genital orifice interrupted by transverse divisions (Fig. 17B).
Etymology. The specific name comes from the Latin word "globous" meaning "ball or sphere" and the name of Dr. Geoffroy Nevill, who first recognized this as a new species and introduce the name "globosa" but was unavailable (see Remark of "globosa").
Distribution. This new species is known from the type locality in Tak Province, western Thailand. In addition, NHM specimens indicate that this species is also found from Chittagong, Bangladesh.
Diagnosis. This new species is distinguished from A. globonevilli Sutcharit and Panha, sp. n. by having a more ovate to elongated conic shell of entirely uniform bright yellow colour. The reproductive organ lacks a vaginal pouch, the penial verge is small and conical. Living snails have an entirely whitish to creamy body; only older snails are likely to have a pale brown head-foot. Superficially, this new species resembles A. flavus from northern Thailand and Laos. However, this new species exhibits a bright yellow, slightly ovate shell, shorter expanded lip and thickened shell, while A. flavus has a slender, pale yellow shell, wide expanded lip with faint spiral band below periphery (Fig. 7I, J).
Internal wall of penis corrugated into series of thin and longitudinal penial pilasters (pp), which form a thin fringe around penial verge. Penial verge (pv) short conic, surface with thin irregular furrow (Fig. 17C).
Female reproductive organ similar to former described species but differs in that vagina internal wall possesses swollen and nearly smooth longitudinal vaginal pilaster (Fig. 17C, D).
Etymology. The specific epithet is derived from the Latin "principalis" meaning "leader" and refers to Her Royal Highness Princess Maha Chakri Sirindhorn who chaired the Plant Genetic Conservation Project as a Royal Initiation to support biodiversity in Thailand. The malacological survey on Koh Kra in 2000 was part of an expedition supported by this project.
Distribution. This new species is known only from the type locality. Remarks. Amphidromus principalis Sutcharit & Panha, sp. n. is known only from the type locality, the granitic island. The forestation type on the island was dry evergreen forest, the snails were found crawling on the tree leaves, trunks or branches of almost all trees up to 10 m height. We also explored two other satellite islands but found no Amphidromus on these islands or any other terrestrial snails other than subulinids.