172 THOMAS SAY FOUNDATION 



silvery pollinose, the latter with the usual row of hairs 

 below, some of which are quite bristle-like; frontal 

 bristles about 12, widely diverging below and reach- 

 ing the middle of the second antennal joint; ocellars 

 of good size; antenna brownish black; third joint 

 twice the second and reaching four-fifths of the way 

 to the vibrissas, w^hich are at about the oral margin; 

 arista with the usual plumosit3> extending a little over 

 half its length; bucca fully one-third the eyeheight; 

 back of head with three and partly four rows of black 

 hairs, together with numerous pale ones; palpi and 

 proboscis black, ordinary; outer vertical bristles not 

 differentiated. 



Thorax whitish pollinose, with the usual 3 to 5 

 black stripes, the submedian gray stripes partly di- 

 vided by a narrow dark line ; hairs of the thorax erect 

 and long ; ps dc four ; ant acr not differentiated ; prsc 

 one distinct pair ; stpl three ; scutellum with two pairs 

 of marginals, one large preapical, and one rather 

 large apical. 



Abdomen silvery pollinose, tessellated, with a 

 distinct median and a pair of changeable lateral 

 stripes, the former shining. First and second seg- 

 ments with only lateral bristles; third with an inter- 

 rupted row of about ten; fourth with a strong row of 

 about 20. 



Hypopygium entirely black; first segment polli- 

 nose, with erect fine hairs and no bristles ; second seg- 

 ment shining, globose, with abundant erect hairs ; for- 

 ceps black, with dense recumbent black hair, especial- 

 ly near the base, varying in form apically, either slen- 

 der or blunt and toothed ; accessory plate brown, with 

 dense long hair, the basal angle acute and apical end 

 truncate; both pairs of claspers shining black or 

 brown, of similar shape, curving forward to a slender 

 sharp point; penis brownish, basal segment distinct; 

 on the back it bulges into a globose form, across the 

 middle of which is a distinct suture, beyond this is a 

 brown sclerite rapidly narrowing into a sharp apical 

 point; this sclerite bears on each side a long, slender 



