Revision of the spider genus Mystaria Simon, 1895 (Araneae: Thomisidae) and the description of a new genus from the Afrotropical region

The spider genera Mystaria Simon, 1895 and Paramystaria Lessert, 1919 are revised (Mystarini: Thomisidae). About 400 individuals were studied. The approach followed was classical taxonomy using illustrated sexual dimorphic copulatory characters and described morphological characters, photographed or measured. Paramystaria is considered a junior synonym of Mystaria , based on similarity to the type M. rufolimbata Simon, 1895 but with the exclusion of M. unicolor Simon, 1895 , a species last studied in 1895. Mystaria unicolor is re-described and placed in a new genus, Leroya gen. n. , together with L. silva sp. n. (♂♀, DRC) which is recognised as the type species. Mystaria now contains 13 well-defined species, four of which are in new generic combinations. Four males are described for the first time, and eight new species. Re-described species include M . flavoguttata Lawrence, 1952 , M . lata Lawrence, 1927, M. . M. (♀♂, Zimbabwe), M . soleil sp. n. (♀♂, Uganda, Kenya) and M . stakesbyi sp. n. (♀♂, Ghana, DRC, Kenya, Rwanda, Tanzania, Uganda). The insufficiently known taxa Paramystaria decorata Lessert, 1919 and P. variabilis delesserti Caporiacco, 1949 are also transferred to Mystaria . Keys are provided to species and related tribal genera, with geographic distributions of species recorded. Revisions of more genera are needed, in particular of those genera related to Mystarini, before phylogenetic relationships can be considered.


Introduction
This paper, the 11 th in a series by Dippenaar-Schoeman on the family Thomisidae of the Afrotropical region, forms part of a revision of the tribe Mystarini; the genera Mystaria Simon, 1895 and Paramystria Lessert, 1919 were revised ( Table 1). The genus Mystaria was described by Simon (1895) represented by the type species M. rufolimbata Simon, 1895 andM. unicolor Simon, 1895, both collected from Sierra Leone. In the revision, these two species were carefully studied and found to have no similar diagnostic characters which indicated that they may not be closely related, and consequently, are not considered to represent the same genus. TABLE 1. Six tribes of the Dietinae of the Afrotropical region and their associated genera as recognised by Simon (1895) and listed by Roewer (1954).
A second genus, Paramystaria from Tanzania was described 24 years later by Lessert (1919), and included two species, P. variabilis Lessert, 1919, the type species, and P. decorata Lessert, 1919. Another two species were subsequently added, namely, P. lata Lawrence, 1927 from Namibia, and P. flavoguttata Lawrence, 1952 from the Democratic Republic of Congo (DRC). Due to colour variation, differing eye distances and cephalothorax form in P. variabilis, two subspecies were recognised by Millot and Capariacco, namely, P. v. occidentalis Millot, 1942 from Republic of Guinea and P. v. delesserti Caporiacco, 1949 from Kenya. Lessert (1919) diagnosed Paramystaria and the type, P. variabilis on the presence of cheliceral teeth on the pro-and retromargin of the cheliceral furrow . However, after examining the type species of Mystaria, M. rufolimbata, it was also proven to have three small teeth on the cheliceral margins as was observed by Jézéquel (1964). The presence of these small teeth was observed in all the species described in Paramystaria. Such small characters possibly may not have been visible to Simon (1895) without modern technology such as SEM and sexually dimorphic characters such as the copulatory organs were not yet used to identify species. On the other hand, teeth on chelicerae in M. unicolor are absent, only long setae on the edge of the promargin are present.
Mystaria rufolimbata, and all species of Paramystaria share similar morphology, not only with respect to their chelicerae, but also in eye patterns, clypeal length, variable abdominal and leg patterns and copulatory organs. The median ocular quadrangle (MOQ) is small with clypeal length equal to or slightly shorter than MOQ length. Apparent individual abdominal patterns vary within and/or between species. Copulatory organs in females include simple epigynes and complex coiling intromittent canals while males have a disc-shaped tegulum, long, coiling emboli and delicate retro-lateral tibial apophysis (RTA).
Based on the similarities in all of these characters, Paramystaria is here recognised as a junior synonym of Mystaria and all the species are transferred to Mystaria. However, this decision entails the exclusion of M. unicolor, which does not possess small cheliceral teeth, having only serrated setae on the cheliceral edge. Added to this, it differs in the above-mentioned characters as follows: posterior median eyes very small, clypeal length much shorter than MOQ length and body without patterns. Copulatory organs in females are recognised by a dark epigynal mark, without coiling intromittent canals. Males lack the coiling emboli but rather possess a short, thickened embolus and strong RTA. Therefore M. unicolor and L. silva n. sp. are included in the new described genus Leroya. . SEM photographs of chelicerae of Mystaria species. 1 M. rufolimbata Simon, 1895 from Democratic Republic of Congo, Walikale; 2 M. flavogutatta (Lawrence, 1952) comb. n. from South Africa, Richards Bay; 3 M. savannensis sp. n. from South Africa, Kruger National Park, Letaba Camp; 4 M. soleil sp. n. from Kenya, Kakamega; 5 M. budongo sp. n. from Kakamega. Scale lines = 100 μm (1,4,5), 10 μm (2,3). Members of the genus Mystaria are plant dwellers and are well known only from the African region. Geographical records show their range to be extended from Ethiopia in the north, Republic of Guinea in the west, along the eastern shore to the Eastern Cape Province in South Africa. They commonly hang from their own silk thread while eating prey. The material examined was collected mostly from vegetation such as shrubs and grasses as well as from the tree canopy of indigenous forests, some were found near coastal beaches, estuaries, rivers, wetlands and forest areas. Members of Leroya gen. n. are rare in collections and little is known about their ecology and behaviour. Collected specimens are from tropical rainforests in Central Africa. The description format and the abbreviations of morphological terms used in the present study for the most part follow terminology explained in Ono (1988). All specimens examined were preserved in alcohol, causing loss of the original bright colouring observed in live specimens (Fig. 6). The following character abbreviations were used in the present study, Body: AL-abdomen length; AW-abdomen width; CL-carapace length; CW-carapace width; CH-carapace height; Clyp-clypeus: CLL-clypeal length; SL-sternum length; SW-sternum width; and TL-total length. Eyes: AER-anterior eye row; AME-anterior median eyes; ALE-anterior lateral eyes; PER-posterior eye row; PME-posterior median eyes; PLE-posterior lateral eyes; MOQ-median ocular quadrangle; MOQ-L-median ocular quadrangle length; MOQ-W-median ocular quadrangle width; MOQ-AW-median ocular quadrangle anterior width; and MOQ-PW-median ocular quadrangle posterior width. Legs: Fe-femur; Pat-patella; Tib-tibia; Mt-metatarsus; and Ta-tarsus. Palp: VTA-ventral tibial apophysis; and RTA-retrolateral tibial apophysis.

Material and methods
All characters were examined using stereo and compound microscopes. Characters were examined under 40 x magnification using a Wild M3C light microscope (Wild, Heerbrugg, Switzerland) fitted with a calibrated 10x micrometer ocular lens, with measurements being recorded to the nearest 0.01 mm. A Vickers compound microscope (Vickers Instruments Limited, York, England) was used to study copulatory organs, and drawings were made with the aid of a Camera Lucida (Leica-Leitz Wetzlar, Vienna, Austria). A Nikon DXM 1200 digital camera (Nikon, Tokyo, Japan) was used for photography on both a Nikon SMZ 800 stereo microscope (Nikon, Tokyo, Japan) and a Nikon Optiphot compound microscope (Nikon, Tokyo, Japan).
For SEM, structures such as tarsal segments of the legs, chelicerae and male and female copulatory organs in spider samples preserved in ethanol, were dissected, air dried and mounted on double-sided carbon tape on aluminum stubs. These were then sputter-coated with gold to a thickness of ca 15-20 nm. Mounted samples were then viewed under a JEOL JSM-840 scanning electron microscope (JEOL, Tokyo, Japan) at an accelerating voltage of 5 kV in order to obtain high magnification photographs.
Quantitative morphological characters in the present study were mainly adopted from those previously defined and used by Ono (1988). Thirty three quantitative measurements per specimen were recorded using an ocular micrometer on a Wild M3C light microscope and included both linear dimensions as well as ratios. About five specimens of each sex per species were studied and measurements recorded to the nearest 0.01 mm. All measurements in study are given in millimeters.
List of measurements and ratios included in this study ( Fig. 7): Length, height and width measurements: CH-carapace height (measured on higher thoracic lateral side of carapace); CI-carapace index (length of carapace divided by width); CL-carapace length (measured from clypeus anterior edge to carapace posterior edge); CLL-clypeus length (measured from the anterior edge of clypeus to AME); and CW-carapace width (over widest part of carapace).
Eye distances and ratios: Anterior eye ratios: AME-AME/AME-ALE (ratio of distance between AME to distance between AME and ALE). Anterior eye row: distances between AME-AME (measured from the centre of AME = MOQ-AW) and (AME-ALE) (measured from the centre of AME to the centre of ALE). ALE/AME (ratio of the diameters of ALE and AME); Clyp/AME-AME (ratio of clypeus length to the distance between AME). MOQ: quadrangle delimited by distances between four median eyes: MOQ-L = AME-PME (distance between the centre of AME to the centre of PME); MOQ eye ratios: MOQ-AW/MOQ-PW = AME/PME (ratio of the anterior width to the posterior width of MOQ); MOQ-L/MOQ-W = MOQ-L/MOQ-AW/PW (ratio of the length to width of MOQ). Posterior eye ratios: PME-PME/PME-PLE (ratio of distance between PME to distance between PME and PLE). Posterior eye row: distances between (PME-PME) (measured from the centre of PME = MOQ-PW) and (PME-PLE) (measured from the centre of PME to the centre of PLE); and PLE/PME (ratio of the diameters of PLE and PME); Sternum dimensions: SI-sternum index (ratio of the sternum length to its width); SL-sternum length (measured over the longest part of the sternum); and SW-sternum width (measured over the widest part of the sternum).
Leg dimensions: Fe, Pat, Tib, Mt, Ta were measured for leg I, II, III, IV on the lateral side of each segment and the sum is given as the total length of each leg. Leg formula is given from the longest to the shortest leg e.g. II:IV:I:III. Abdomen dimensions: AI-abdomen index (ratio of abdomen length to its width). AL-abdomen length (measured from the anterior edge along a mid-dorsal line to the posterior edge); AW-abdomen width (measured over the widest part of the abdomen); Body length: TL-total length (the sum of CL and AL). The copulatory organs were dissected using either tweezers or a minute needle mounted on a wooden stick. In males, the left palp (Fig. 8), where available, were removed, at the patella. In females the epigynes (Fig 9) were carefully removed by lightly poking around the epigyne margin, from the ventral side of the abdomen thereby lifting out the internal copulatory organs. The dissected male and female copulatory organs were temporarily mounted on a slide in a polyvinyl alcohol solution (PVA) (Kranz & Walter 2009) and placed under both a Vickers compound microscope and Nikon Optiphot compound microscope to study and to photograph. The dissected structures were subsequently stored together with their associated specimens in small glass vials.  Simon, 1895. Jézéquel 1964: 1111Ono 1988: 32. Paramystaria Lessert 1919; type species by original designation: Paramystaria variabilis Lessert, 1919. Diagnosis. Small spiders, body and/or legs usually decorated with spots or bands (Figs 12,15,21,36). Median eyes equal in size, smaller than laterals, with MOQ area narrower in front. MOQ length only slightly shorter or longer than clypeal length. Chelicerae equipped with three small teeth (Figs 1-5). Epigyne rim simple with simple outlines (Figs 51,59,73,81), intromittent canals with numerous complex coils (Fig. 74). Male with simple bulb, disc-shaped tegulum, long coiling embolus, tibia with VTA curved at tip and delicate RTA (Figs 71,72,87,88).
Colour. Carapace at times with patches or bands, may differ between individuals within a species or in case of males usually uniform. May have dark patches over eye region or a yellow patch on clypeus and AME area (Figs 20,33,40); abdomen usually with varying patterns or often uniform in case of males. Colours and bands on legs differ between species. Carapace. Circular to cube-shaped viewed from above, elevated in thoracic and sometimes cephalic region, truncated posteriorly, sloping slightly anteriorly (Figs 11,12); smooth without setae to fairly dense covering of fine setae, usually more dense in cephalic region and on clypeus, sometimes with longer erectile setae on postero-thoracic and postero-lateral region, and around lateral eyes (Figs 38,39). Clypeus. Vertical with or without long setae. Chelicerae. Three cheliceral teeth present, two on promargin and one on retromargin (Figs 1-5), with incurving serrated setae at tip on dorsal margin of chelicerae. Mouth parts. Labium triangular, usually longer than wide, endites converged and indented with scopula hairs on edge. Sternum. Heart-shaped, usually wider than long, anterior edge straight; posterior tip not extending beyond coxae IV; edge bordered. Eyes. AER recurved; AME<ALE; AME closest to each other; PER recurved, slightly wider than AER; PME<PLE; PME nearest to PLE; MOQ area wider than long; lateral eyes situated on small flattened tubercles. Legs. Long and slender, with second pair usually longest in females, leg formula: II:I:IV:III, males with first pair of legs usually longest, leg formula: I:II:IV:III, long to medium length setae present; usually two spiniform setae ventrally on tibiae and metatarsi, distally on all legs; scopula hairs denser on leg III and IV; trichobothria present in a row on all legs; two dentated tarsal claws (Figs 91-114) with a well-defined, thick base in females, less defined base in males, with approx. 12 long slender teeth present on all tarsal claws, fewer and shorter in males with the second tooth usually on legs III & IV or II modified (flattened or broadened). Abdomen. Round to oval, bearing numerous short setae; dorsally with seven sigillae grouped in arrow-shaped formation (Fig. 17), ventrally with small sigillae in two rows; striae present ventrally around abdomen edge and dorsally of spinnerets, males with scutum, rarely with bright patterns on body (Figs 10,13,16). Spinnerets. Small and conical, with numerous short setae; anterior pair largest. Epigyne. Simple or delicate rim (Fig. 47,67,77) and atrium with ( Fig. 85) or without hood, intromittent orifices open laterally or antero-laterally on atrium; intromittent canals long and extended then curving back, forming numerous complex coils, shape usually differs slightly on both sides; spermathecae small, round, situated posteriorly; fertilisation tubes short. Palp. Tibia bearing long setae; bulb round, often with tutaculum (Figs 8, 61); embolus thin ( Fig. 45) or thick, of medium to long length (Fig. 43), coiling approx. three times around bulb; RTA sometimes broad at base (Fig. 75), proximally tooth-like and slender (Figs 49,53), to broad (Figs 43,45) or long and slender, extending far beyond the tutaclum (Figs 61); VTA with curved tip, long almost similar length as RTA (Fig. 66).
Natural history. Members of Mystaria live on vegetation such as trees, shrubs, grasses or leaf litter in a diversity of natural areas including: savanna, woodland, grassland, canopies of rainforests, forest galleries, coastal dune-, sand-and riverine forests in river banks, swamps, wetlands, estuaries, valleys and mountains. Adults are found throughout the year.
Female. Unknown. Zootaxa 3873 (2)  Natural history. Specimens were collected from primary and secondary forest canopy using fogging. They were sampled from various tree species such as Carapa grandiflora, Cynometra alexandri, Rinorea beniensis and Teclea nobilis. Only males are known and they were sampled between October and February.
Description. Female. Size, measurements (n = 6). TL Colour. Carapace varies from orange with black line around postero-lateral border (Fig. 15), with or without two dark patches over LE region (Fig. 14) to blackish-copper specimens, often with orange triangular patch on clypeus, colour and body patterns may vary between individuals; abdomen very pale with dark, longitudinal central band that may expand laterally, or with two darker patches laterally; ventrally pale with pale blue stria. Carapace.
Natural history. Sampled from riverine, sand, dune and coastal forest as well as woodlands and grasslands. Samples were found in trees such as Terminalia sericea and Acacia sieberiana. Most adults were sampled between September and March, while juveniles were sampled in December. One of the specimens sampled was hanging on its own silk thread from a tree while feeding on a bee (P. Reavell, pers. comm.).
Distribution. Mozambique and eastern parts of South Africa (Fig. 117).
Distribution. Namibia and South Africa (Eastern Cape Province, new record: KwaZulu-Natal Province) (Fig.  118). Etymology. Named after Linda Wiese who collected the holotype in the Eastern Cape Province, the southernmost locality for this genus in South Africa. Adjective.
Distribution. South Africa (Eastern Cape and Western Cape Provinces) (Fig. 119). Natural history. Sampled from vegetation in forests and garden. Adults collected between December and July. Etymology. 'Mnyama' means black in Zulu, as this species is recognised by the black-tinted areas on the cephalic and eye area. The name is to be treated as a noun in apposition.
Diagnosis. Females recognised by colour patterns on body (Fig. 26); differ from other species which may have similar abdominal patterns by slightly larger lateral eyes which are situated closer to PME; epigyne with atrium rim teardrop-shaped, small flap posteriorly; small intromittent orifices open antero-laterally (Fig. 67). Male dark with pale legs, femora I and II may have dark infuscated bands (Fig. 28); RTA with long slender tip directed laterally with slight curve anteriorly (Fig. 65); VTA slender (Fig. 66).
Natural history. Sampled from sweeping and beating vegetation such as trees shrubs and from forest litter in coastal beach forest, gallery forests, marshy areas near lakes and mountainous areas. Collected material suggested adults to be abundant from July to April whereas juveniles appeared from March to June.
Diagnosis. Females can be recognised by the colour patterns on body. Femora I-IV infuscated totally or partially with brown band (Figs 29, 30). Epigyne with atrium rim horseshoe-shaped, small hood centrally (Fig. 69). Male unknown.
Type material: Lectotype (by present designation): ♀, SIERRA LEONE (MNHN). Syntype series (designated by Simon 1895) from MNHN is examined. One female is elected as a new lectotype from the syntype series.