300 THOMAS SAY FOUNDATION 



joint three times the second, reaching five-sixths of 

 the way to the vibrissse, which are at the oral margin ; 

 arista long-plumose for about three-fifths of its 

 length; palpi and proboscis black, the former rather 

 short and clavate; bucca one-fourth the eyeheight, 

 with only black hairs before the suture ; back of head 

 with two or three partly irregular rows of black hairs 

 and a few pale ones in the middle and below ; the pos- 

 terior orbit of the eye with decidedly yellow pollen. 



Thorax yellowish gray pollinose, with the usual 

 three to five black stripes, which are brown when 

 viewed from in front ; the submedian gray stripes are 

 divided to the suture by a narrow dark line, which 

 appears light on a dark ground when viewed from 

 in front; ps dc four, all quite large; ant acr well de- 

 veloped, three or four pairs ; prsc one paii* ; stpl three ; 

 scutellum with three marginal pairs, the intermediate 

 ones small ; one subapical which might in this case be 

 called subdiscal, and the apicals represented only by 

 minute hairs. 



Abdomen gray pollinose, tessellated, with three 

 dark stripes not very changeable; first and second 

 segments with only lateral bristles; third with a 

 median marginal pair and sometimes a few smallish 

 ones forming a weak marginal row; fourth segment 

 hardly at all red on the hind margin, with the usual 

 marginal row of bristles; fifth sternite blackish on 

 the exposed part, broadly excised in the shape of a 

 U, the tips of the arms slightly turned out from the 

 body but not with noticeable brush or bristles. 



Hypopygium yellow, first joint more or less in- 

 fuscated at the base, pollinose, with a few scattered 

 bristles near the apex; second segment subshining, 

 without bristles; forceps reddish yellow except the 

 tips, which are shining black. Viewed from behind 

 they are widely divergent near the base and then al- 

 most parallel ; viewed from the side they curve rather 

 evenly forward, tapering to a sharp point. Accessory 

 plate small, yellow, the apex rounded; both claspers 

 entirely yellow, erect at base and strongly curved for- 



