18 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 63, 



GYROPUS GRACILIPES. new species. 



Text tig. 7. 



A long slender species, with the posterior legs more slender than 

 the middle ones. Head as broad as long; temporal lobes with 

 rather sharp lateral angles. Antennae about filling the antennal 

 fossae ; inner margin of last segment longer than the outer and very 

 strongl}' curved, outer margin almost straight, sensory pit con- 

 spicuous but not deep. Palpi not reaching the outer margin of 

 labrum and with all four segments very distinct. Prothorax al- 

 most as broad as the head, anterior margin almost straight and 

 lateral margins subparallel toward the front but strongly divergent 



posteriorly. Mesothorax abqut twice as 

 broad as long and almost as broad as 

 the prothorax, its sides diverging pos- 

 teriorly. Metathorax about as broad 

 and as long as the prothorax, its sides 

 diverging posteriorly. Abdomen fully 

 twice as long as broad, sides almost 

 parallel and end of abdomen in female 

 truncate. The abdomen is clothed with 

 long conspicuous setae. Gonopods of 

 female rudimentary, but each with the 

 usual conspicuous fringe of setae, the 

 two inner ventral of which are exceed- 

 ingly minute, the third and fourth are 

 stoutest, approximate and subequah 

 Genital armature of male conspicuous, 

 compact, and well chitinized; basal 

 plate long, with sides slightly concave 

 and divergent posteriorly. In the fe- 

 male the first and second pairs of legs 

 subequal, with the last pair smallest. 

 First pair of legs of male the largest 

 and the last pair the most slender. Tarsal thumb of male as in G. 

 latipollicaris. Femur III longer and narrower than femur II and 

 with the tenaculum greatly reduced; tibia III much longer and 

 considerably narrower than tibia II ; tarsus III (fig. 7) much more 

 slender than II and with transverse striations much less pronounced ; 

 tarsal claw III considerably longer and sharper than tarsal claw II. 

 Length of female, 1.69 mm.; width, 0.60 mm. Length of n»ale, 

 1.68 mm. ; width, 0.57 mm. 



Type host and type locality. — Ctenomys colburni from Huanuluan, 

 Rio Negro, Argentina. 

 Type slide.— C&t. No. 23761, U.S.N.M. 



Fig. 7. — Gtropds gracilipes 

 Posterior view of tarsus III, 



