6l6 CALIFORNIA ACADKMY OF SCiENCKS. 



cies is to be distinouished from J", isabclliiia Will, by the 

 absence of brown lines on face and cheeks, by more ex- 

 tensive contiguity of eves in male, by the much smaller 

 vertical triangle, and bv the black of hind margins of sec- 

 ond and third abdominal seg-ments being obsolete. 



The specimens differ from Williston's description of 

 lata (Biol. C— A., Dipt., iii, 45—6) by having the hairs of 

 front and face wholly black; the antenna^ not what I 

 should call '' ver}' small"' ; the dorsum of thorax with four 

 faint blackish cinereous stripes, the lateral ones abbrevi- 

 ated before, the middle ones behind; and by the seg- 

 ments of the abdomen being of a more uniform smoky 

 yellowish. They can hardly be that species. 



43. V'OLUCELLA SODOMIS n. Sp. 



El Taste, Baja California (Eisen). September. Two 

 ^ . Differs from V. cstcbaiia as follows : 



Length, 8 mm. Frontal triangle wholly shining pol- 

 ished black, extending below base of antenna; on each 

 side in a tuberculous extension, strongly convex. Ab- 

 dominal markings nearly the same, but the second seg- 

 ment more broadlv blackish on median portion of disk. 

 Venter darker. Wings distinctly flavous on anterior half 

 or more. 



44. V^OLUCKLLA TOLTECA Towns., Trans. Am. Ent. 

 Soc, 1895. El Taste, Baja California (Eisen). Sep- 

 tember. One female and one male. Length, 8 mm. 

 These agree very closely with the 3 specimen from Guan- 

 ajuato, Afexico, which is described in Contrib. Dipt. N. 

 A. i, in Trans. Am. Ent. Soc, 1895. They differ only 

 in being smaller, and in the posterior black border of 

 second abdominal segment quite reacliing the lateral 

 maroin, I am inclined, however, to regard them as the 

 same species. The brown clouds of wings are less dis- 

 tinct. 



