Description of two new species of Tonsilla Wang & Yin, 1992 with an updated key to species (Araneae, Agelenidae)

Abstract Two new species of Tonsilla Wang & Yin, 1992 are described from Jinggang Mountain National Nature Reserve, Jiangxi Province, China: T.jinggangensis K. Liu & X. Xu, sp. nov. (♀) and T.subyanlingensis K. Liu & X. Xu, sp. nov. (♂♀). The new species are illustrated, and their distributions are mapped. Detailed generic characters and an updated key to Tonsilla species are also given.


Introduction
At present, the Coelotinae, with approximately 770 species belonging to 33 genera, is the largest subfamily of Agelenidae. The number of species in this subfamily has increased in the last five years greatly due to more than 20 publications, so that now the Agelenidae is the tenth largest spider family (WSC 2020). More than half of the species of Coelotinae belong to 24 genera and are known from China (WSC 2020); therefore, China has most species-and genus-rich fauna in the world. However actual species richness in the region remains unrevealed.
Tonsilla Wang & Yin, 1992 is relatively small genus with 11 named species which are known exclusively from China. It is a relatively well-studied genus due to numerous publications (see WSC 2020), although half of the species are known by a single sex only (five by females and one by a male). Only one species was described from Jiangxi Province (Zhu et al. 2017).
While studying the Agelindae from the Jinggang Mountain National Nature Reserve, Jiangxi Province, we found two new species belonging to Tonsilla, and the main goals of this paper are, therefore, to describe these new species, to provide a key to all species of the genus, and to discuss the affinities of Tonsillia.

Materials and methods
Specimens were examined using a Zeiss Stereo Discovery V12 stereomicroscope with a Zoom Microscope System. Both the male palps and female copulatory organs were detached and examined in 75−80% ethanol under a Zeiss Axio Scope A1 compound microscope with a KUY NICE CCD. For SEM photographs, the specimens were dried on filter paper and photographed with the ZEISS EVO LS15 scanning electron microscopes under a low vacuum. The specimens were subsequently stored in 75% ethanol after SEM.
All measurements were made by using ImageView CM2000 software and in millimetres. Leg measurements are given as total length (femur, patella, tibia, metatarsus, tarsus). All the specimens are deposited in the Animal Specimen Museum, Life Science of College, Jinggangshan University (ASM-JGSU).
Terminology of the male and female copulatory organs follows Wang (2003) and Wang et al. (2010). Leg spines are documented by dividing each leg segment into three aspects, dorsal and ventral, the latter being divided into prolateral and retrolateral, e.g., I femur 0 (dorsal) 2 (prolateral ventral) 2 (retrolateral ventral); I tibia 1 (dorsal) 4 (prolateral ventral) 4 (retrolateral ventral). An asterisk (*) indicates a slender spine. The abbreviations used in the text and figures are: Eyes ALE anterior lateral eye; AME anterior median eye; PLE posterior lateral eye; PME posterior median eye; Type species. Tonsilla truculenta Wang & Yin, 1992. Diagnosis. Males of this genus can be easily distinguished from these of other genera of Coelotinae by the male palpal patella with a large strong apophysis, which is more than half of the patella length (Figs 5D, E, 7F) (vs small, less than half length of palpal patella in other genera) and conductor with dorsal apophysis (Figs 5C-E, 7A-C, E) (vs without dorsal apophysis). Females of Tonsilla are most similar to those of Pireneitega in having the large epigynal atrium and large copulatory ducts, and easily differentiated from them by the sub-spherical spermathecae (Figs 1D, 2B, 6D, 7I) (vs strongly convoluted) and from other genera by epigynal teeth located on the anterior atrial margin close to each other (Figs 1C, D, 2A, B, 6C, D, 7H, I) (vs widely separated epigynal teeth located bilaterally in other genera).

Male
Description. Body size 7.0-17.0 mm. The morphological appearance of this genus is similar to that of other coelotines. Carapace anteriorly narrowed to between 0.6 and 0.9 times its maximum width. PLE-PLE covered half width of anterior carapace. Chelicerae (Figs 1B, 6B) robust, as wide as half of carapace, with long fang, usually with 3 promarginal and 2 or 3 retromarginal teeth. Endites (Figs 1B, 6B): bean-shaped, longer than wide, with a relatively narrow base, ectal margins distinctly convex; ectal edge concave. Labium: longer than wide, posteriorly narrowed. Sternum (Figs 1B, 6B): longer than wide, shield-shaped, almost straight anteriorly, with slightly convex sides, and pointed posteriorly.
Male palp (Figs 5C-E, 7A-G): patella with large apophysis, more than half of the patella length, strongly sclerotized, extending to dorsal part of patella; tibia with 2 apophyses, ventroretrolateral and retrolateral, the former broad, arising basally, extending along the retrolateral margin, anteriorly with slightly protruding beyond the distal or subdistal part of tibia, with widely truncated tip, the later from small to large, arising latero-medially; cymbium length/width ratio varies 1.8-2.4 in dorsal view, cymbial furrow less than half of cymbial length, in T. defossa and T. subyanlingensis sp. nov. from half to more than half of cymbial length; conductor long, anterior part with a distinct furrow or without, with a bifurcated tip or not, with a fine dorsal apophysis of conductor arising from its base; embolus flat and thin, arising at 6 o'clock position, with broad basally, roundly bent and coiled; tegular apophysis spoon-like.
Epigyne: atrium from large to small, heart-shaped, posteromedially located, broad and anteriorly located in T. defossa, with an arch-shaped or triangular septum arising antero-medially in T. truculenta Wang & Yin, 1992; copulatory openings located postero-laterally in the atrium; epigynal teeth tube-shaped or horn-like, flattened in T. subyanlingensis sp. nov., located antero-medially, separated by its length or less, or slightly fused basally; copulatory ducts sac-shaped, mostly rounded, tube-shaped in T. jinggangensis sp. nov., T. subyanlingensis sp. nov., and T. yanlingensis; spermathecae spherical or ovoid, duct-shaped in T. defossa, widely separated or close to each other; spermathecal heads arising anteriorly or posteriorly, from short or long; fertilization ducts arising from the posterior part of spermathecae.
Distribution and habitat. The genus is known from subtropics in south China (Sichuan, Anhui, Guizhou, and Jiangxi provinces). Habitats of these spiders are not very diverse, usually found in woody debris, among tree roots on the ground, in humus, and under stones or tree bark.  Diagnosis. The female of this species is similar to that of T. yanlingensis but differs by the long horn-shaped epigynal teeth (vs short, bell-shaped in T. yanlingensis), the widened posterior part of atrium (vs narrowed in T. yanlingensis) and the slender spermathecal heads (vs relatively short and curved in T. yanlingensis) (Figs 1C, D, 2, 3).
Carapace brown. Chelicerae red brown. Endites, labium, and sternum yellowbrown. Legs yellow-brown. Abdomen dark brown, dorsally with 2 pairs of yellowbrown spots from antero-median to middle and 4 yellow-brown chevron-like stripes in posterior half.
Epigyne (Figs 1C,D,2,3). Atrium deep, transverse, more than 2 times wider than long. Copulatory openings located at postero-lateral part of the atrium. Epigynal teeth long, horn-shaped, separated by its length, apex slightly convergent. Copulatory ducts slightly longer than spermathecae, originating posteriorly, extending forward along spermathecae and connected to anterior part of spermathecae. Spermathecae arched, with many constrictions, separated by less than radius of spermatheca. Spermathecal heads slender tube-shaped, posteriorly located, bent laterally. Fertilization ducts located at the posterior part of spermathecae.
Distribution. Known only from the type locality in Jiangxi Province, China (Fig. 9).
Comments. Although we have only the female of this species, we are convinced that it is not conspecific with T. makros a species known from Guizhou. The male of T. makros (6.20) is slightly larger than half of the female of T. jinggangensis sp. nov. (11.03). Tonsilla species seem to have a narrow distribution, except for T. truculenta   Etymology. The specific name refers to its similarity to T. yanlingensis (Zhang, Yin & Kim, 2000); adjective.
Diagnosis. Females of the new species closely resemble T. yanlingensis by the heartshaped, large atrium and wide epigynal teeth, but can be distinguished by the spermathecae separated by less than 1/5 of their width (vs touching each other in T. yanlingensis), long and broad copulatory ducts along with the spermathecae (vs very short in T. yanlingensis), the slightly procurved spermathecal heads located at posterior part of spermatheca (Figs 5C, D, 7H, I) (vs strong procurved spermathecal heads located at mid part of spermatheca in vulva), and the spermathecae slightly separated by less than 1/5 of their width (vs touching each other) (Wang and Yin 1992;Zhu et al. 2017). The male of this species is similar to that of T. mopanensis and T. truculenta in having a long, broad, and furrowed basal lamella of conductor, but can be separated by the patellar apophysis which is relatively shorter than patellar (vs as long as patellar apophysis in T. mopanensis or longer in T. truculenta) and the conductor with a long, broad curved dorsal apophysis (Figs 5A-C, 7A-G, 8A-C) (vs long, narrowed in T. mopanensis; short, strong in T. truculenta).
Lighter than male. Abdomen, dorsally with four indistinct yellow-brown chevronlike stripes on posterior half.
Epigyne (Figs 6C, D, 7H, I, 8D, E). Atrium with a transverse depression, broad, more than 2 times longer than its length, heart-shaped, anterior margin near the apex of teeth, posterior part relatively broad. Copulatory openings located at postero-lateral of the atrium. Epigynal teeth flat, separated by less than their length, apex slightly converging. Copulatory ducts, originating laterally, extending forward along spermathecae, then back, but located at lateral part of spermathecae. Spermathecae egg-shaped, clearly separated by less than 1/5 their width. Spermathecal heads relatively broad, short, posteriorly located, curved laterally. Fertilization ducts located at the posterior part of the spermathecae.
Distribution. Known only from the type locality in Jiangxi Province, China (Fig. 9).