168 THOMAS SAY FOUNDATION 



Abdomen black and silvery, with three change- 

 able stripes and the usual tessellation; first and sec- 

 ond segments with only lateral bristles ; the third with 

 median marginal hairs and laterals; fourth with a 

 marginal row of about 12. 



Hypopygium black ; first segment with consider- 

 able gray pollen and slender erect hairs, but no bris- 

 tles; second segment shining, reddish on the lower 

 border, with rather abundant erect hairs ; forceps dark 

 brown, rather large, in profile straight and parallel 

 for more than half of the free portion, then broadly 

 curved forward, ending in a small tooth which is just 

 behind the middle of the apex. Viewed from behind, 

 they are flat and united for more than half of their 

 entire length, then separated by a U-shaped excision 

 which narrows a little apically and then widens sud- 

 denly ; the whole posterior surface is shining and cov- 

 ered with small recumbent hair, which as usual is 

 longer at the base. Accessory plate slender, brown, 

 the free part nearly half as long as the forceps ; pos- 

 terior clasper brown, nearly straight, tapering rapid- 

 ly near the tip, where it is strongly curved forward; 

 anterior clasper much larger, broad and stout, yellow 

 or brownish yellow, the posterior side deeply and 

 broadly grooved almost to the apex, which is not 

 hooked. The basal segment of the penis brown, rather 

 square, of considerable length ; distal segment in gen- 

 eral outline rather square, having the appearance of 

 being attached at one corner; from this point of at- 

 tachment four chitinized processes develop; one of 

 these, the posterior one, forms the back of the seg- 

 ment, bending in a rounded angle and proceeding to 

 the apex, where it is broadly flattened and lighter col- 

 ored; it is smooth and shining throughout its course; 

 two of the processes form lateral supports, spreading 

 out on the two sides of the central structure; the 

 fourth one projects forward and is quite short; from 

 the middle of the segment two wide plates extend for- 

 ward, while the apical part spreads out in a transverse 

 plate armed with a slender hook. Fifth sternite 



