Gymnostreptus trimarginatus ( Gervais, 1847 ) Mauriès & Golovatch & Hoffman, 2001

Mauriès, Jean-Paul, Golovatch, Sergei I. & Hoffman, Richard L., 2001, On type material and the identity of several Iulus species described by Paul Gervais, in the collection of the Muséum national d’Histoire naturelle in Paris (Diplopoda, Spirostreptida, Spirobolida), Zoosystema 23 (3), pp. 579-589 : 584-585

Gymnostreptus trimarginatus ( Gervais, 1847) n. comb.

( Fig. 2 )

Iulus trimarginatus Gervais, 1847: 189 ; 1859: 22, pl. 3, fig. 2.

TYPE MATERIAL. — N° IB 103, 1 subadult lectotype, 4 paralectotypes.

TYPE LOCALITY. — The samples are said to derive from Brazil, collected by Wauthier (recte: Vauthier), a French traveler who visited Brazil in 1831-1833 ( Papavero 1971). He apparently collected chiefly around Rio, but also in Minas Gerais around Diamantina. So whatever Gymnostreptus anyone tries to match up with trimarginatus would probably be one occurring in one of those two regions.

REMARKS

Though type material of this species contains a single subadult male and four fragmented females (with the anterior body part of one of the latter selected herewith as lectotype, the other specimens as paralectotypes), it appears possible to safely attribute trimarginatus to Gymnostreptus as well. New illustrations are provided here for comparative purposes ( Fig. 2 ), yet already Gervais’ figure 4 in the 1859 paper clearly shows the collum to have a conspicuous caudolateral emargination that seems characteristic only of very few nominal Gymnostreptus species. Thus, a virtually identical to highly similar condition is found in G. bovei (Silvestri, 1895) , from Paraguay and Argentina ( Hoffman 1997), G. deserticola (Brölemann, 1902) , from Sertão de Pernambuco, Brazil (only known from the female sex, too, hence treated as incertae sedis by Krabbe 1982), and G. iheringi (Brölemann, 1902) , from many places in Brazil (cf. Krabbe 1982, who assigned this species to Hemigymnostreptus Schubart, 1950 , although Hoffman 1975a treated it as a Gymnostreptus ). Yet it would seem premature to synonymize any of these names as there are minor differences in somatic characters expressed between them. Judged from peripheral features alone, especially the pattern of collumnar striation and the strongly margined anal valves, G. trimarginatus seems to come closest to, if not identical with G. iheringi . Further material is necessary to finally resolve the riddle of the identity of both G. trimarginatus and G. deserticola . Indeed, the conspicuously emarginate collum might prove to be a good character reflecting phylogenetic relations between congeners, in spite the unsettling case related by Krabbe & Enghoff (1985).

Family IULOMORPHIDAE Verhoeff, 1924

Figures

FIG. 2. — Gymnostreptus trimarginatus (Gervais, 1847), lectotype; A, anterior body end (lateral view); B, midbody segment (lateral view); C, telson (lateral view). Scale bar: 2.0 mm.