Eight new species of the spider genera Raveniola and Sinopesa from China and Vietnam (Araneae, Nemesiidae)

Abstract Eight new species, seven Raveniola Zonstein, 1987 and one Sinopesa Raven & Schwendinger, 1995 from China and Vietnam are described: Raveniola alpina sp. n., Raveniola bellula sp. n., Raveniola chayi sp. n., Raveniola gracilis sp. n., Raveniola rugosa sp. n., Raveniola spirula sp. n. and Raveniola yajiangensis sp. n. and Sinopesa ninhbinhensis sp. n. Keys to all East-Asian congeners, diagnoses of the new species, and new distribution data of Raveniola montana Zonstein & Marusik, 2012, with a first record for Sichuan, China, are provided.

While sorting and identifying nemesiid material in the Institute of Zoology, Chinese Academy of Sciences, eight new species belonging to Raveniola and Sinopesa were found; they are described here. The systematic position of both genera was recently considered by Zonstein and Marusik (2012). The latter genus was shown to be more closely related to the former rather than to the African Entypesa Simon, 1902 as suggested by Raven and Schwendinger (1995).
To permit reliable identification and stimulate further studies in this area, all new descriptions are illustrated and keys to the studied genera and species are added.

Material and methods
Specimens were examined and measured with a LEICA M205 C stereomicroscope and details were studied with an Olympus BX51 compound microscope. Illustrations were made using a camera lucida attached to the Olympus BX51 microscope and inked with an ink jet plotter. Male palps and female genitalia were examined and illustrated after they were dissected from the spiders. Vulvae were treated in a warm solution of 10% potassium hydroxide (KOH). The left palp and left legs I and II of male spiders were illustrated, unless otherwise indicated. Specimens were preserved in a 75% ethanol solution. Photos were taken with an Olympus C7070 wide zoom digital camera (7.1 megapixels) mounted on an Olympus SZX12 stereomicroscope. The images were assembled using Helicon image stacking software. All measurements are given in millimetres unless otherwise noted. Leg measurements are given as: total length (femur + patella + tibia + metatarsus + tarsus). Leg segments were measured on the dorsal side.
All specimens used in this study are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing, China. The only exception is the female paratype of R. chayi sp. n., kept at the Senckenberg Museum, Frankfurt am Main, Germany (SMF). 1 Thoracic fovea short, U-shaped; posterior sternal sigilla distinctly larger and farther from sternal margin than other sigilla, in many cases subcentral or confluent; paired tarsal claws either with two more or less distinctly juxtaposed teeth rows (females) or with one S-shaped row ( & Schwendinger, 1995, has two enlarged retroventral distal spines on tibia I in males and divided receptacles in females, as well as the absence of a serrula and metatarsal preening combs. The leg scopula in Raveniola is more developed than it is in Sinopesa. By contrast, the male intercheliceral tumescence in Raveniola is lost or vestigial, whereas in Sinopesa, it is well-developed. Like Sinopesa, members of Raveniola have more or less reduced PMS, which are completely lost in some species. The apical segment of the PLS in Raveniola is usually shorter than that in Sinopesa.

Key to East Asian Raveniola species
Females of R. alpina sp. n., R. gracilis sp. n., R. guangxi, R. rugosa sp. n., R. shangrila, R. songi, R. spirula sp. n. and R. yunnanensis are unknown. Palpal tibia relatively short, with a length/width ratio of 3.0-3.2 ( Fig  Tibia I equal in length to or shorter than metatarsus (as in Fig. 17E). Few spines on cymbium (as in Fig. 19A Abdomen with dorsal and ventral spotted pattern (  Etymology. The specific name is taken from the Latin adjective "alpinus", which means "alpine" and refers to the high altitude of the type locality.  Diagnosis. The new species is similar to R. chayi sp. n., R. shangrila and R. songi, all also occurring in Yunnan, but differs by the slightly twisted and bent distal portion of the embolus (Figs 1A-C, 2A-C, cf. Figs 6A-C, 7A-C). R. alpina sp. n. can be distinguished from the latter species also by the absence of PMS (present in R. songi).
Female. Unknown. Distribution. China: northern Yunnan. Etymology. The specific name is taken from the Latin adjective "bellulus" (the diminutive form of "bellus"), which means "beautiful" and refers to the perfect shape of the palpal bulb.
Diagnosis. This new species is similar to R. chayi sp. n. and R. yunnanensis but can be distinguished by having a considerably shorter embolus than that in R. chayi sp. n. ( Zonstein and Marusik 2012: figs 35, 43). Females are characterised by the unique shape of the receptacles, divided into a long, digitiform inner branch and a short, knobshaped outer branch (Figs 4A, 5D). The habitus and the abdominal pattern of R. bellula sp. n. resemble that of Sinopesa maculata, but it is distinguished by generic characters, such as well-developed body and leg setation and by much longer and denser tarsal scopula.
Variation. Total length of males: 9.49-11.10 (n=8). Etymology. The specific name is taken from the Latin adjective "gracilis", which means "slender" and refers to the shape of embolus.
Diagnosis. This new species can be easily distinguished from all known congeners by its slender and subapically curved embolus (Figs 9A-C, 10A-C).
Female. Unknown. Distribution. The species is known only from the type locality. Diagnosis. This species can be easily distinguished from all known East Asian congeners by its short and stout palpal tibia and by a short and flattened embolus ( Fig.  11A-C), combined with the presence of ridges on the wide proximal portion of the embolus (Fig. 12A-C) and the unique shape of the receptacles in females (Zonstein and Marusik 2012: fig. 48).
Distribution. China: northern Yunnan and southern Sichuan.  Etymology. The specific name is taken from the Latin adjective "rugosus", meaning "wrinkled" and refers to the wrinkled transition between embolus and bulb.
Diagnosis. The new species is similar to R. chayi sp. n. but can be distinguished by its embolus gradually curved to the tip (twisted in the latter species) and by the considerably better developed embolic ridges (Figs 7A-C; cf. 14A-C). It can be distinguished  from R. montana, which also possesses embolic ridges on the bulb, by a much longer palpal tibia and a longer embolus (Figs 12A-C; cf. 14A-C).
Female. Unknown. Distribution. The species is known only from the type locality.  Etymology. The specific name is taken from the Latin noun "spirula" (the diminutive form of "spira = spiral"), which means "small spiral" and refers to the spiral embolus.
Diagnosis. The new species is similar to R. yunnanensis but can be distinguished by a noticeably longer and less spinose cymbium, by its more twisted, corkscrew-shaped distal portion of the embolus (see Fig. 16A-C and Zonstein and Marusik 2012: figs 35, 43) and by the absence of PMS (present in the latter species).

Genus Sinopesa Raven & Schwendinger, 1995
Type species. Sinopesa maculata Raven & Schwendinger, 1995, by the original designation. Diagnosis. Sinopesa, like Raveniola, differs from Hermacha and Entypesa by lacking serrula and metatarsal preening combs and by possessing two enlarged retroventral spines in males and divided receptacles in females. As in members of Raveniola, the PMS in Sinopesa are reduced in size and even lost in some species -a condition which has never been observed in Hermacha and Entypesa. Sinopesa differs from its close   relative Raveniola by a thin and less developed scopula and by the presence of a welldeveloped male intercheliceral tumescence (which is less developed in Raveniola and completely lost in all Chinese members of this genus).
Composition. Six species -S. chengbuensis (Xu & Yin, 2002) Raven & Schwendinger, 1995 (Thailand) and S. sinensis (Xu & Yin, 2002) (China). The new species is described below.   Etymology. The specific epithet, a Latinised adjective, refers to the type locality. Diagnosis. The new species shares with S. kumensis the complete absence of an abdominal pattern and the presence of a short male palpal tibia, but it can be distinguished from the latter species by the complete absence of PMS and by the presence of a globular bulb and of a gradually tapering and apically hooked embolus (oval and corkscrew-shaped, respectively) in S. kumensis (see Figs 20A-C, 21A-C, and Shimojana and Haupt 2000: figs. 3A-B).