332 PROCEEDINGS OF THE RATIO'S AL MUSEUM. vol.43. 



Subfamily HYSTRICIII^^E;. 



CESTROHYSTRICIA, new genus. 



Allied with Epalpodes, Andinomyia, and Vihrissomyia, from all of 

 which it may be at once differentiated b}" the much broadened abdo- 

 men and densely placed spinelike macrochsetse of abdomen and scutel- 

 lum. The description is drawTi from a single female. Front broad 

 and produced, at vertex rather more than \Nidth of one eye, broaden- 

 ing rapidly to face. Parafacials but httle longer than wide, thickly 

 beset with fine long hairs, these continued on parafrontals. Cheeks 

 gi'eatly mdened and lengthened, as wide as eye-height and about one 

 and one-half times as long as same, thinl}^ set with bristly hairs. 

 Peristomal bristles nearly same strength as vibrissse, slightly shorter, 

 about same as the two bristles which occur above vibrissse, all directed 

 same as latter. Epistoma extremely produced anteriorly beyond 

 the peristomalia, the profile of upper half of facial plate being almost 

 parallel with plane of occiput, the lower half of facial plate directed 

 anteriorly downward from upper half at an angle of about 45°. 

 Vibrissal angles not narrowing the facial plate. Second antennal 

 joint elongated, third joint a little shorter than second and wider. 

 Arista rather short, bare; basal joints short but distinct, hardly 

 longer than wide. Frontal bristles slender, descending obhquely not 

 quite as low as base of third antennal joint. Two slender prochnate 

 orbital bristles, a pair of long delicate hairhke. ocellar bristles. Eyes 

 bare. Proboscis elongate and horny, part beyond geniculation 

 hardly equal to head-height; palpi very small and short, vestigial. 



Thi'ee sternopleural bristles, four very weak and hairhke postsutural 

 bristles. A median pair of spinehke macrochsetse close to hind mar- 

 gin of mesoscutum. Scutellum with two pairs of strong lateral bris- 

 tles, four heavy suberect spinelike marginal macrochsetse between 

 them, two shorter submarginal median ones, and several still shorter 

 erect ones on disk. Scutellum is very widened and shortened, nearly 

 three times as wide as long, transversel}" subequilateral but bulged in 

 middle. Abdominal macrochsetse are as follows: First segment with 

 no dorsal, 5 or 6 lateral in a bunch, and a median ventral patch 

 formed of about 18 in a widely open V-shaped double row. Second 

 segment with 8 or 9 lateral in patch; more than median one-third of 

 dorsum of segment covered with short erect ones, and a marginal row 

 of 8 or 10 (9, 5 being on one side and 4 on other, these being slightly 

 separated by a median submarginal pair like the median posterior 

 pair of mesoscutum) heavy erect ones ; venter of segment with median 

 patch of 12, 9 being in an open V-shaped single row. Third segment 

 without discal, with a marginal row composed of long heavy ones 

 interspersed with much shorter ones, a median submarginal short 

 pair, outside of which are 2 widely separated heavy ones ; venter of 



