164 Mr. R. I. Pocock on new Sjjecies of Chilopoda. 



by a fine transverse sulcus which runs just behind the poste- 

 rior terminations of the longitudinal sulci ; the covered portion 

 of the sternites defined by a strong, arched, forwardly convex, 

 transverse groove. 



Anal somite. — Tergite not sulcate, with raised margins, its 

 posterior border slightly and convexly produced in the middle ; 

 pleurce thickly covered anteriorly and inferiorly with circular 

 close-set pores, posteriorly and superiorly smooth, the process 

 smooth, slender, and simple, the internal edge of the posterior 

 surface chitinous and subserrate ; sternite wide, closely 

 embracing the pleuras, narrowed posteriorly, posterior surface 

 concave ; legs somewhat sliort, hairy, hairs on tarso-meta- 

 tarsus longer and more scattered than on the other segments ; 

 the femur, patella, and tibia subequal in length, the patella 

 being, however, slightly the longest; femur triangular in 

 section, armed beneath with a series of five spines, its upper 

 inner border furnished with a few minute spinules, its upper 

 surface posteriorly notched ; patella furnished below in its 

 anterior half with a single small spine ; tibia unspined ,• tarso- 

 metatarsus not so long as the femur and patella taken together, 

 evenly thick throughout and indistinctly multiarticulated 

 throughout, the proximal segment neither thicker nor longer 

 than the others. 



Legs. — Twenty-second pair absent, twenty-first pair infe- 

 riorly hirsute, unarmed, twentieth pair also hairy; tibia 

 armed distally with an anterior and an inferior spine, and the 

 tarso-metatarsus with an inferior setiform spine ; claws basally 

 spurred, tarso-nietatarsus indistinctly divided. 



Length up to 22*5 millim., of anal leg 6*5. 



Two specimens from George Town, Demerara, sent to the 

 British Museum by Mr. J. J. Qaelch. 



Allied to N. mexicana and N. Ernsti in having the seg- 

 ments of the anal tarso-metatarsus indistinctly defined and 

 very numerous. 



From both it diff"ers in that the proximal segment of the 

 anal tarso-metatarsus is of the same size as, and in all respects 

 similar to, the rest of the series. From mexicana it further 

 differs in having the tibia of the anal leg unarmed and the 

 upper inner edge of the femur at most furnished with a few 

 minute spinules ; and from N. Ernsti it may be recognized 

 by the form of the sulci on the first tergite and head, the 

 area defined by this tergal sulcus being in N. Ernsti ovately 

 convex and marked by two distinct longitudinal sulci, whereas 

 in N. hrevipes it is very indistinctly divided and circularly 

 convex ; in this last species again there is no posterior trans- 

 verse sulcus on the head-plate. 



