Xystonotus madagascariensis Pešić, Cook & Gerecke, 2013

Xystonotus madagascariensis Pešić, Cook & Gerecke sp. nov.

( Figs. 41G–H View FIGURE 41 A – H , 44A–F View FIGURE 44 A – F )

Type series: Holotype female, dissected and slide mounted, Madagascar 109, Ankaratra (Antananarivo), Reserve Manjakatompo, riparian spring exp. SE, at spring stream N deviation to Analamitana (MD108), 1850 m asl., 14.3˚C, 0.003 mS/cm, 08.x.2001, Gerecke & Goldschmidt. Paratype: same locality and data as holotype, 0/1/0 (dissected and slide mounted).

Diagnosis (based on female; male unknown). Dorsal shield with V-shaped area of smaller pores only slightly raised laterally, reaching frontal and caudal margin of dorsal shield, more distanced to each other in their middle part, leaving a broader medial, and narrower lateral areas ( Figs. 41 View FIGURE 41 A – H G-H); gnathosomal bay a rounded V-shaped; medial margin of Cx-IV reduced to a median angle; genital bay of moderate depth, embracing approximately onehalf of the genital field ( Fig. 44E View FIGURE 44 A – F ); genital field noticeably wider than long (L/W ratio 0.9); Cxgl-2 located anterior to gonopore; ventral tubercle of P-4 truncate.

Description

Female ( holotype, in parentheses measurements of paratype): Idiosoma (ventral view: Fig. 44B View FIGURE 44 A – F ) L/W 434 (475)/378 (394). Dorsal shield ( Fig. 41 View FIGURE 41 A – H G-H) L/W 398 (428)/341 (347), ratio 1.17 (1.23); gnathosomal bay L 65 (65); gonopore L/W 83 (86)/94 (92), ratio 0.9 (0.9); egg maximum diameter (127). Palp ( Fig. 44C View FIGURE 44 A – F ): total L 165-167 (163); L/H, L/H ratio: P-1, 20/25, 0.8 (20/25, 0.8); P-2, 39/40, 0.98 (37/40, 0.93); P-3, 35/31, 1.12 (32/32, 1.0); P- 4, 52-53/28-29, 1.9 (55/28, 2.0); P-5, 19-20/10, 2.0 (19/9, 2.1); chelicera total L 92 (89); gnathosoma vL 82 (80). Legs: dL of I-L: 60 (59), 59 (59), 45 (48), 50 (51), 63 (65), 77 (74); I-L-6 H 36 (33), I-L-6 dL/H ratio 2.1 (2.2); dL of IV-L: 69 (72), 60 (71), 59)63), 79 (83), 99 (103), 92 (105).

Male: Unknown.

Etymology: Named after the country of the type locality.

Discussion: Due to the shape of the posteromedial suture lines of Cx-IV which extend abruptly posteriorly and closely flank the genital field, the new species is assigned to the subgenus Mixomideopsis which also includes Xystonotus ( Mixomideopsis) sandola (Cook) from South Africa. The later species is unique within the genus Xystonotus in that the legs bear a few swimming setae (numbers: III-L-3/4 and IV-L-4, 1, III/IV-L-5, 2), Cxgl-2 being located close to anterolateral margin of genital field, and P-4 very slender with a proximally placed ventral tubercle.

Distribution: Madagascar; only known from the type locality in the Ankaratra mountains.