Remarks on the genus Plexippus C. L. Koch, 1846 (Araneae: Salticidae)* 1

The database of the genus Plexippus C. L. Koch, 1846 is revised following methodology of morphological comparisons, recommended by “Pragmatic classification” proposed by Prószyński (2017). Comparison of selected diagnostic characters (palps, epigynes and external appearance of body) confirms very insufficient state of knowledge of the genus, due to separate study of individual species by subsequent authors. That situation is disadvantageous for comprehension of the diversity within the genus, resulting in impossibility of identification of majority of species. There are cases of mixing up species, which cannot be resolved without revision of type specimens. Paper presents a sort of blueprint for revision of the genus. The following new taxa are described in this paper.


Introduction
History of research on Plexippus illustrates pitfalls of taxonomic studies of poorly known genera. During XIX century large number of diverse species was described as, or transferred to Plexippus. The Bonnet's "Bibliographia Araneorum" (1958: 3712-3722) list 70 species of Plexippus accepted at that time, as well as 86 synonymic names. In the World Spider Catalogue (assessed in 2017) the number of valid species is reduced to 39, however, survey of diagnostic documentation by Prószyński (2016aPrószyński ( , 2016b documents only 8 recognizable species, having both sexes known, and another 12 half recognizable species (that is known from single sex specimens), 23 other names cannot be assigned to any recognizable species without additional revisions. Personal contribution of Prószyński (1971Prószyński ( , 1984Prószyński ( , 1987Prószyński ( , 1992Prószyński ( , 2009) to that reduction amounts to 43 species transferred to other genera, in a result of detailed study of their palps and internal structures of epigyne. Recently two important papers dealing with particular species from India and Thailand were added, respectively by Caleb (2016) and by Żabka & Gardzińska (2017), both with perfect and exemplary modern diagnostic documentation. The later is setting a modern standard of documentation of a species of Salticidae (Fig. 1), expected to be provided for each of 4376 recognizable species, and all other species pending revision. Unfortunately graphic documentation published in literature is often incomplete, or of quality not permitting perception of details (too small, photographs not sharp, drawings diagrammatized), which contribute to frequent misidentification in publications presented in our time.
Survey of species inside genus Plexippus shows inadequacies resulting from separate study of single species, or a few species only. Modern authors accept generally main characters defining the genus: unique palp and epigyne structure (although preparations of ducts and spermathecae is included only by some authors), but fragmentary knowledge of full scale of diversity limits interpretations of characters. Only knowledge of all species permits to see and understand gaps in our knowledge. For instance omission of revision of type specimens of Plexippus devorans makes identification of several species valueless, substitution of drawings of species from Greece by "the same" drawings from Turkmenistan make record of European fauna untrustworthy (see discussion of the case below). Onset of documentation of species by color photographs in electronic publication is exceptionally useful for documentation. Study of all species separately cannot equal understanding gained from study of all species in a single project, as a taxonomic revision.  (Karsch, 1878, male A-F and female A1-F1), as befitting in 2017. It consists of precise diagnostic drawings of palps -E-F, epigyne and internal structure of epigyne E1-F1, repeated also as color photograph (to reduce inadequacies resulting from subjective interpretation by an artist) -D-D1, color photographs of unchanged habitus of specimens of both sexes (dorsal, frontal and ventral views, missing lateral view ) A-C1. The size of individual illustrations permits clear perception of diagnostic characters.

Plexippus auberti Lessert, 1925
Figures 4J, 6B-B1 has somewhat diagrammatized appearance, I delay comments on the described above discrepancy, until new, revisonary data become available. I must add, however, that narrowness of the epigyne's pocket and furrow shown by Logunov, resembles features of epigyne of syntype of "Attus" devorans O. Pickard-Cambridge, 1872a: 327 "Attus devorans Cambr.""41", "jar 1739" [original label of the species described as Salticus devorans] kept in the same collection -I abstain temporarily from commenting on that coincidence, the remaining syntypes of that species are kept in the NH Museum in London, not yet revised. More information on that species -see Plexippus devorans, below. Similarity of palps of P. clemens from Egypt and India with palps of P. similis from Yemen (Figs 3J1) poses question of correctness of identification, and previously suggested synonymy with female ( Fig.  5C-C1), originally described as P. similis Wesolowska & van Harten, 1994. These questions cannot be answered without further research. Remarks. Plexippus coccineus Simon, 1902a: 403 is unrecognizable from the original description of a single male, collected in Turkomania (historical name of the area between Persia and Georgia, exact meaning in this description is uncertain), original specimen kept in the Simon collection in MNHN-Paris (Prószyński 1971: 459) was not revised. Synonymy with Plexippus strandi Spassky, 1939, proposed by Nenilin 3 , 1985a: 132 (Fig. 8) is not supported by examination of specimen and diagnostic graphic documentation, therefore is not acceptable. Therefore: Plexippus coccineus: Nenilin, 1985 -identification not documented, synonymy not accepted.  Prószyński (2016a, b) and current literature.

Remarks. Species described on several specimens -"Adults and immature examples of both sexes [of
Salticus devorans] were found on walls, rocky banks and among stones on the plains of the Jordan. An adult male was also met with at Rasheiya [XIXth century station between Banias and Damascus, on the spur of Mt. Hermon, in present day in Lebanon]" -which suggests that the species may be more common in typical environments in Israel and widely distributed in the Levant. Palp shown in Fig. 4C belongs to a specimen found unlabeled[?] in a jar with Palestine collection may, by elimination of other possibilities, MIGHT BE a stray male of "Attus devorans" because unique, more anterior position of prolateral swelling of embolar basis and its shorter distance from embolus itself, which is broader than in other species. Pickard-Cambridge lists from Palestine males of only that species of Plexippus. While this hypothesis cannot be taken as proof of placement of the specimen, the puzzle it presents may be solved only by comparison with syntypes kept in NH Museum in London. Perhaps mentioning it in this description may stimulate identification of remaining syntypes.

Conclusions.
Lack of knowledge of internal structure of epigyne in syntype specimen drawn by Prószyński (1984: 85), together with lack of taxonomic revision of syntype specimens of this species kept in NH Museum of London, makes uncertain all subsequent identification of that species. Anterior position of the epigynal pocket (Fig. 5G) excludes all species with central pocket, narrowness of epigynal furrow excludes broad furrowed forms (like P. similis). It resembles drawings f. 11-12 in Logunov (2010) claimed to represent holotype of P. clemens (by the way O. Pickard -Cambridge 1872 uses both names "devorans" and "clemens" in combinations with "Salticus", changed later by Simon 1876 for "Hasarius" and "Euophrys" respectively, however, on original labels both names are used in combination with "Attus" -changes of mind in such matters are frequently encountered in old collections) kept in the same jar. Problem could be disentangled by redescription and good diagnostic drawings of syntypes of Plexippus devorans (= " Hasarius" devorans) kept in Natural History Museum in London (Prószyński 1971: 412), which may possibly cause necessity of renaming other species reported from the Near East.  Prószyński (2016a, b) and current literature.

Diagnosis. Differs distinctly from
Plexippus strandi by color pattern of body, with notable absence of transverse black belt in the anterior abdomen, a character noticed by Andreeva (1976: 88, f . 121-124). Palp resembles P. strandi, but prolateral part of embolar basis seems to be less swollen and located more symmetrically along the length of bulbus. Epigyne with pocket located centrally, seems to be larger than in P. strandi.
Description (condensed translation of original Russian description by Andreeva). Male carapace yellow covered by indistinct whitish setae, except eyefield covered with brownish red setae, with indistinct spot of white setae, and thin black line along ventral edge. Eyes III located on pair of black spot, there is an indistinct, elongated spot of dark setae along posterior one third of posterior slope of thorax. Legs and palps brownish yellow, with longitudinal spots of dark setae, clypeus with dense and long white "beard". Abdomen dorsally yellow, with two lateral reddish brown streaks. Length of body 5.5 mm. Female. Carapace (damaged) dark brown with eyefield still darker. Eyes Median Anterior surrounded ventrally by whitish setae, dorsally brownish red. Clypeus, chelicerae and palps brown with whitish setae, legs brown without white setae. Abdomen dark with light median streak, beginning from diamond shaped spot. Length of body 6.2 mm .
Remarks. The description require completing by more precise drawing documentation, especially providing drawing of internal structure of epigyne. Placement of dushabinus as a subspecies of P. strandi disagree with principles of taxonomy limiting description of subspecies only to interpopulational studies. Without populational research on P. strandi there are no reason to suggest populational relationships of these forms. Differences in color pattern are sufficiently distinct to elevated this subspecies to the rank of full species. Therefore: Plexippus strandi dushanbinus = Plexippus dushanbinus (Andreeva, 1969) -elevated to rank of full species.

Plexippus fibulatus Dawidowicz & Wesolowska, 2016 Figures 2O, 4P
Material. Holotype male and 2 paratypes males from Kenya: Mt Elgon, Suam River, 2100 m. Coll. A. Holm is not overlooked during study and its absence is real, the species cannot be placed in the genus Plexippus and should be reclassified elsewhere. Figures 2M, 4N-O, 6C-C1, 7H-I Hissarinus kondarensis Charitonov, 1951: 215, f. 7 (Dmf). Hissarinus kondarensis Andreeva, 1969: 90, f. 2 (mf). Plexippus kondarensis Andreeva, 1975: 339. Plexippus kondarensis Andreeva, 1976: 88, f. 116-117 (mf). Plexippus kondarensis Prószyński, 1976: 156, f. 280 (m). Plexippus kondarensis Logunov & Rakov, 1998: 129, f . 43-46 (mf). Description (condensed original description by Charitonov 1951Charitonov : 2015. Male carapace yellow with 3 pairs of irregular dark spots of short, adpressed black setae: the first very small, and arranged transversally, just beyond eyes I, the second and third larger, in mid length and in posterior half of carapace. Light spaces laterally and between dark spots covered with short, adpressed white setae. Clypeus covered with long "beard" of yellowish white setae, overhanging also cheliceral bases. Orbital setae below anterior eyes, both median and lateral are white, above light orange. Sternum light yellow with white setae. Legs yellow, patellae and tibiae I-II yellowish grey except tibia I, which is dark brown, densely covered with long, black setae. Femora I-IV with longitudinal dark spots on anterior and posterior surface, white scales on distal parts of anterior surfaces of femora I-II, patellae I-IV with triangular lateral spots. Female. Appearance of carapace less differentiated than in males, anterior half grayish brown, passing onto lighter posterior half, orange spots on lateral surfaces. Legs pale. Longitudinal streaks on abdomen less sharp than in male. Total body length is given as 7.6 mm for male and 8.1 mm for female.

Distribution.
Tadjikistan: Varzob Valley, including Kondara, also Kvak, Ramit. Comment. Palp does not resemble genus Plexippus (Fig. 4R) and the author did not present any argument for placement of this species. Therefore species should be reclassified elsewhere.  Prószyński (2016a, b) and current literature.

Remarks.
Existing descriptions of P. setipes are incomplete and diagnostic drawings are confusing, depicting apparently three different morphs. I assume that female type specimen of this species (Figs 7L1, 9A, I-J) collected by Hilgendorf in Japan is the only unquestionable female of this species. I hypothesize that female illustrated on Figs 2H, and 9C from Japan may be conspecific because of indistinct median streak on abdomen, therefore matching male may also be P. setipes (Figs 2H, repeated on 9B). It is characterized by unusual transverse white belt, following red one, in anterior eyefield, occurring also in Vietnamese specimen (Figs 7L3, 9D). Male palps of these specimens are shown on Figs 9R-S -(the latter looking somewhat differently). Differences of palps of all three morphs lies in slightly different shapes and proportions, which are not clear cut and may be interpreted in various way, therefore identification of males should be based on color pattern characters, which are, however, imprecisely documented for some specimens.

Remarks.
It seemed, at certain time, that similarity of epigyne of this species and P. clemens (compare Figs 5D-D1 with B-B1) is sufficient to consider them synonyms. However, learning of epigyne of several other species permitted to notice differences: proportions of length of epigynal furrow, breadth of ducts and shape of spermatheca, also palps, seem intermediate between P. clemens and P. bhutani (compare Figs 3J1 with J, and also B) in length of tibial apophysis, thickness of embolus and space separating it from serrated edge of swelling of embolar base. Since these difference concern mainly proportions of parts, some residual of incertitude remains, pending of more complete comparative research of fresh, or live specimens.
Distribution. Yemen.  Spassky, 1939  Figures 4H, K, 5I-I1, K-K1, 6E-F, 7D, E, 9F-H, N-P, V-W Description. Male. Carapace dark brown with traces of white, adpressed setae, with white, thin thoracic streak expanded into large, regular round spot in the foveal area (Fig. 2Q1), delimited from eyefield by fawn transverse line. Sides light fawn with whitish adpressed setae, with dark brown margin along ventral edge of carapace. Abdomen with median light streak, followed laterally by a pair of dark brown streaks, expanded further on sides and ventral surface. There are four white chevrons on posterior half of light streak, interconnected medially. Posterior angle of abdomen dark, dorsal spinnerets dark brown with lighter tips. Face uniformly dark brown, eyes I surrounded by yellow setae. Clypeus dark brown, almost bald, with a few longer gray setae under AME, stretching diagonally and overhanging chelicerae, there are also sparse peculiar setae swollen apically on clypeus and entering chelicerae. Chelicerae dark brown. Palps light brown to yellow, cymbium dorsally with contrasting round, white spot of adpressed setae. Line of adpressed white setae terminally on femur and along patella. There is characteristic retrolateral "flag" -bunch of dark, brown or black setae on palpal femur. Palpal organ -see Figs 4F-G. Legs brown with mosaic of black spots: leg I dark brown with apical end of tarsus yellow, leg II brown with darker metatarsus, III-IV yellow with brownish shade. Length of body 3.4 mm.

Plexippus strandi
Paratype male is much lighter, possibly due to fading, with darker areas brown, whitish setae on yellow background are less striking. Dark areas on thorax consist of adpressed brown, elongated scales, also on abdomen dark spots consist of brown, adpressesd scales. Palpal organ and "grey flag" on palpal femur as in holotype specimen. Legs yellow.
Female (allotype). Eyefield light brown, covered by unnoticeable, colorless adpressed scales. Thorax yellow with sparse darker, brownish olive adpressed setae, concentration of which makes four elongate darker spots on posterior slope of thorax. Face light yellow with sparse, white setae on clypeus, white setae encircling eyes. Chelicerae creamy yellow, arising horizontally and almost immediately bending perpendicularly down. Pedipalps yellow with sparse, long, stiff setae dark and whitish. Abdomen pinkish yellow, with lighter median, light delimited streak, lateral part of dorsum darker brown, due to adpressed brown scales, anteriorly group of longer, dark bristles, There is a pair of white spots in four fifth of length of abdomen, encircled by dark brown scales. Spinnerets dark yellow. Abdomen ventrally lighter pinkish yellow. Sternum and coxae yellow with pinkish hue. Epigyne covered by waxy secretion blurring its shape, its correct appearance become visible after bath in KOH solution (Figs 5E-E1). Legs yellow with short and sparse dark setae. Length of body 5.5 mm.
Plexippus cf. tectonicus-photographs of a live male specimen from Yemen -(Photo B. Knoflach, published in Wesolowska W., van Harten A. 2007. Fauna of Arabia, 23: 246-248, f . 33-36) show a species resembling closely Plexippus tectonicus but differing by intensely black coloration of carapace, abdomen and legs I, with contrasting white pattern, but the white foveal spot, anteriorly to thin petiole, is not round but diamond shaped. Setae around lateral external half of eyes I median are reddish (those on median half of these orbits are white) and correspond with red orbital setae around eyes I lateral, while median parts of orbits I are white (Figs 2Q-S). White spot on cymbium is striking, "flag" on palpal femur consist of both black and white setae. Lack of specimens do not permit to study palps. I assume that the species should be closely related to P. tectonicus, but separate. Diagnosis. Epigynal pocket located centrally, very narrow. Epigyne and its internal structures somewhat different from usual in Plexippus so the placement of species is uncertain.

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