Two new species of Diaphorocellus Simon, 1893 from Madagascar (Araneae, Palpimanidae)

Two new species of the palpimanid genus Diaphorocellus Simon, 1893, D. isalo sp. nov. (♂♀), and D. jocquei sp. nov. (♂♀), are described from central and eastern parts of Madagascar, respectively. Along with D. rufus (Tullgren, 1910), these new species can be distinguished from other congeners by possessing a finely and densely spotted colouration of the abdomen. They differ from one another, as well from D. rufus, by the eye group configuration and by the structure of the male and female copulatory organs. Diagnoses and illustrations presenting the diagnostic characters of D. isalo sp. nov. and D. jocquei sp. nov. are provided. The genus now includes six African species.


Introduction
The spider family Palpimanidae is relatively well represented in mainland Africa, where it comprises 13 genera and 53 species vs. 18 and 150 respectively, known for the entire world (World Spider Catalog 2019). Palpimanids have also been found in several insular territories/countries located near the African continent: São Tomé and Príncipe (Simon 1907), the Seychelles (Simon 1898;Platnick 1979;Saaristo 2010) and Socotra (Pocock 1899. However, to date, no named species of the Palpimanidae have been reported from the largest of the regional islands, Madagascar, although the occurrence of Diaphorocellus spp. on this island was first noted by Wood et al. (2018).
The present study, which seeks to fill this gap, is based on the examination of palpimanid specimens deposited in the Royal Museum for Central Africa, Tervuren, Belgium (RMCA). Along with other African palpimanids kept in the RMCA spider collection, several species of Diaphorocellus Simon, 1893 were identified during the study. Two of these species, originated from Madagascar, were found to be new to science and are described below.
Currently, Diaphorocellus is a small African genus of palpimanid spiders previously known to include four species whose known distribution is restricted to Tanzania, Botswana, Namibia and South Africa (World Spider Catalog 2019). The aim of this paper is to provide a detailed description of the two new species and to update the diagnostic characters of the genus.

Material and methods
The origin of the material used in this study is noted above.
Photographs were taken using an Olympus SZX16 stereomicroscope with a Canon-7D camera and final images were compiled using Zerene Stacker 1.04 software (https://zerenesystems.com). Scanning electron micrographs were made using a JEOL JSM-5200 scanning microscope at the Zoological Museum, University of Turku, Finland. Illustrations of scuta and endogynes were made after maceration in a 20% potassium hydroxide aqueous solution and exposure for a few minutes in an alcohol solution of Chlorazol Black. Endogynes were photographed on slides with either an Olympus SZX16 or an Olympus BH-2. Background maps were taken from https:// www.simplemappr.net (Shorthouse 2010).
Measurements were made to an accuracy of 0.01 mm. Lengths of leg and palp segments were measured on the dorsal side, from the midpoint of the anterior margin to the midpoint of the posterior margin. All measurements are given in millimetres. Terminology partially follows Zonstein et al. (2016).
Notes. Diaphorocellus appears to be an exclusively Afrotropical chedimine genus that comprises six species: D. albooculatus Lawrence, 1927 (Namibia), D. biplagiatus Simon, 1893 (South Africa), D. helveolus (Simon, 1910) (Tullgren, 1910) (Tanzania). Within the genus, the first three species have a bicoloured dorsal abdominal pattern (presenting a broad longitudinal pale stripe against a dark background, the pale stripe is usually separated into two by a wide dark bridge). These congeners differ from the remaining three species, which have a uniformly and finely spotted abdominal colouration. To date, only the type species, D. biplagiatus, has been redescribed in detail (Zonstein et al. 2016). Etymology. The specific name is a toponym referring to the type locality, Isalo.
Copulatory organs: as in Figs 3B, 7A-D, 8A. Epigastral plate in intact specimen accompanied by 2 pairs of sclerites lying on postgastrum (posterior from epigastral furrow): two small dot-like median sclerites and pair of longitudinal sclerites. Endogyne formed by pair of complex receptacles. Receptacle (Re) consists of complex sclerotised base and transparent, membranous cylindric sac (Figs 7A-D). Each receptacle accompanied by brushes of fine threads and 3 grape-shaped glands attached to receptacles by long thread-like stems.
Habitat. According to the collecting data, the specimens were found near a natural pool in a rocky massif.
Distribution. Known only from the type locality (Fig. 9). Etymology. The specific name is a patronym in honour of the prominent Belgian arachnologist, Dr Rudy Jocqué, for his highly significant contribution to the study of African spiders.   1♀, same collecting data but xii.1993 (RMCA ARA 177889); 1♀, same collecting data but xi.1994 (RMCA ARA 206925).
Diagnosis. The new species can be distinguished from D. isalo sp. nov. by its smaller size and by the shape of the copulatory organs (the latter also distinguishes this new species from non-Malagasy congeners). Males of D. jocquei sp. nov. are characterised by the absence of cymbial spines (vs. present), and by a less dense cymbial brush composed of stronger setae (Figs 4F cf. Fig. 4C). Females of these two species clearly differ in the shape of the membranous sacs: large subconical sacs in D. jocquei sp. nov.  Habitus: as in Figs 1E-F. Colour in alcohol: carapace and chelicerae deep scarlet red; legs I and abdominal scuta intense reddish orange; palps and legs II-IV pale milky orange; sternum, labium, maxillae and pedicel tube medium scarlet red; abdomen dorsally very pale brown with small and dense even paler whitish spots, ventrally uniformly pale milky orange, entirely covered with short and relatively dense brownish setae. Measurements: TL 4.35. CL 2.0, CW 1.85, CH 0.38, CyL 0.32, Femur I L/W 2.09 (1.63/0.78). Carapace: with moderately coarse granulations (Fig. 3C). Eyes: AME 0.18, ALE 0.13, PME 0.09, PLE 0.07; AME-AME 0.09, AME-ALE 0.09, AME-PME 0.07, PLE-PME 0.09, PME-PME 0.02.
Copulatory organs: Palp as shown in Figs 4D-F, 5C-D, 6B-C. Femur 2.7 times longer than wide and 1.34 times longer than cymbium; patella globular, thinner than femur; tibia swollen, as long as wide, 1.55 times wider than femur. Cymbium retrolaterally with relatively sparse brush of strong setae. Bulb globular, partly embedded into the tibia; with 2 long (longer than tegulum) outgrowths: tegular apophysis and embolus. Tegular apophysis with 2 arms, pro-and retrolateral: prolateral arm with kind of comb on inner side; both arms bent on tip. Embolus located prolaterally, flat and long, almost as long as tegular apophysis.
Copulatory organs: as in Figs 3D, 7E-F, 8B. Epigastral plate in intact specimen (before dissection) accompanied by 2 pairs of sclerites lying on postgaster (posterior to epigastral furrow): two small dot-like median sclerites and pair of longitudinal scle-rites. Atrium broad, postgastral plug weakly sclerotised. Endogyne formed by pair of complex receptacles. Receptacle consists of complex sclerotised base and transparent, membranous subconical sac (Fig. 7G). Each receptacle accompanied by brushes of fine threads and 3 grape-shaped glands attached to receptacles by short thread-like stems.
Habitat. According to the collecting data, the specimens were found in the litter and mosses on a forest floor, and in a fern thicket dominated by Asplenium sp.
Distribution. Known only from the type locality (Fig. 9).
The same is true regarding the similar structure of the vulva (with the receptacles closely adjoining one another) in Diaphorocellus isalo sp. nov., D. jocquei sp. nov. and D. biplagiatus ( Fig. 7A-F cf. Zonstein et al. 2016, figs 20, 23-26). It should be noted that not all the figures provided by Zonstein et al. (2016) are correct. When describing the female copulatory organs of D. biplagiatus, we also erroneously included two figures (Op. cit., figs 21, 22) of Palpimanus sp. (from Israel) labelled as belonging to D. biplagiatus.
Both the new species from Madagascar certainly differ from D. biplagiatus in lacking a contrasting abdominal pattern, in possessing untouching posterior median eyes, shorter male palpal tibia (femur 1.2 longer than cymbium vs. 1.7), lack of long retrolateral tibial setae of the male palpal tibia, and the tegulum strongly embedded in the cymbium. The two new species feature an epigastral scutum with an extended petiolar tube; this tube and part of the scutum are provided with about 9-10 circular or subcircular ridges (Fig. 8). They differ from the similarly coloured D. rufus in eye sizes and arrangement. In both D. isalo sp. nov. and D. jocquei sp. nov. the distance PLE-PME only slightly exceeds the diameter of PLE, while in D. rufus, according to Tullgren (1910), the corresponding distance is 1.5 times as long as the diameter of PLE.