CEEATOMYIELLA AND PAEADIDYMA REINHARD 39 



Thorax black ; mesonotum densely gray pollinose, the black stripes 

 usually fused into a single broad pair, which extends to base of 

 scutellum; chaetotaxy as in validinervis ; sides of postnotum beneath 

 calypters usually bare but sometimes with a few small hairs present; 

 calypters white. 



Abdomen black; last three segments with silvery bands on basal 

 third, remainder of these segments including the first polished or 

 shining; basal segment without median marginal bristles; second 

 with one pair ; third and fourth each with a marginal row, the fourth 

 occasionally with one or two discals on the sides but none at middle 

 above; genital segments blackish, retracted; inner forceps black, 

 with a slight median keel behind, moderately broad at base, the 

 apical half narrowed terminating in an acutely tipped shining beak; 

 outer forceps yellow, slightly shorter than inner ones, the sides 

 bulged and clothed with short brownish hairs, tips blunt; fifth 

 sternite with a narrow deep incision, the lobes black. 



Legs black; claws and pulvilli elongate. 



Wings grayish hyaline; third vein with hairs extending almost 

 to small cross vein ; last section of fifth vein one-third the length of 

 preceding section; apical cell closed and usually short petiolate; 

 costal spine well developed. 



Female. — Front at vertex 0.328 of the head width (average of five: 

 0.35; 0.32; 0.35; 0.31; 0.31) ; the usual two pairs of proclinate orbit- 

 als present; outer verticals not developed; antennae shorter than 

 face, third segment slender, about one-half as wide as parafacial 

 and four or five times longer than second; cheek two-fifths the eye 

 height; fourth abdominal segment with a row of discals behind the 

 middle above; fore tarsi compressed, the claws and pulvilli 

 atrophied. 



Length. — 5.5 to 8.5 mm. 



Remarks. — Redescribed from a long series of both sexes from all 

 sections of the United States, including the type male of Lachnomma 

 magnicornis Townsend, in the Kansas University Museum. 



A common North American species described from Carlinville, 

 111. Readily distinguished from most other members of the genus by 

 the two broad black thoracic stripes, which in well-preserved speci- 

 mens are sharply contrasted on entire length by a median and lateral 

 pale gray pollen bands. C atemofliTys sequens Townsend presents 

 about the same general appearance but can readily be separated by 

 its bare eyes and parafacials. 



(23) PARADmYMA PETIOLATA, new species 



Mesonotum subshining, the vittae poorly defined; arista thickened 

 on proximal half or less; apical cell closed, the petiole about twice 

 the length of small cross vein. 



