Vol. xxiii] ENTOMOLOGICAL NEWS 441 
Gyropus ovalis Nitzsch. 
Specimens of this species and of the following from the 
guinea pig, Cavia cobaya, sent in by H. E. Ewing (Urbana, 
Iil.). (Also from Cambridge, Mass., by S. S. Berry.) 
Gyropus gracilis Nitzsch. 
Many specimens (Urbana, Ill.; Cambridge, Mass.). 
Gyropus bicaudatus n. sp. (Pl. XX, Fig. 3). 
A large series of specimens taken by W. M. Mann from a 
wild guinea pig (Cavia cutleri), collected by Dr. W. E. Castle 
in Peru. This species closely resembles in general habit 
Nitzsch’s G. gracilis, but is strikingly different in the form of 
the last abdominal segment in the male. In the present species 
this segment narrows and gives rise to two prominent append- 
ages, each bearing a strong spine, giving the insect a very 
characteristic appearance. ‘This difference is shown in Figs. 
3b and 3c, the former being drawn from specimens of G. gra- 
cilis Nitzsch. | 
Description of male: Entire insect pale, often white or transparent. 
Head closely resembling that of G. gracilis, Nitzsch. Antennal, ocu. 
lar and temporal bands faint, continuous, marginal, enlarged slightly 
around the lateral emarginations; numerous minute hairs on the mar- 
gin of the rounded clypeus and a row across on the surface near the 
margin; also several hairs on the divergent sides before the lateral 
emarginations and on the convergent temples. Thorax narrower 
than head, prothorax almost circular, with posterior margin slightly 
angled on the meson; metathorax quadrilateral, sides slightly round- 
ed. Abdomen long and narrow with sides, between the second and 
sixth segments, almost straight; last two or three segments tapering, 
the last being produced into two appendages (Figs. 3 and 3c), each 
appendage bearing a stout spine; a short fine hair on the lateral mar- 
gin of this segment just above the appendage. In old specimens a 
faint transverse band is visible across each segment; a row of ex- 
tremely minute spines or prickles across each segment. 
Measurements: ¢@ 1.16; @ 1.22. Length Width 
Male Female Male Female 
JIG Cla peo BE Cee 18 18 16 18 
iRrothorax) Sse. ..- 10 .10 Ae 14 
Metathorax ....... 12 12 12 14 
NDOOMEN, Geo, 5.:0:-% e 82 .28 36 
