180 DIPTEEA. 



Female. The whole body, including the legs and antennae, uniformly velvety-black, 

 opaque, except the last four abdominal segments, which are black, shining, and with a 

 thinner covering of hairs; wings as in the male, only a little darker. — Length 

 22-28 millim. 



Besides the difference in the colouring (which may be variable) this species differs 

 from L. mutabilis, Loew, in the following points: — 1. The hairs on the abdomen are 

 much shorter, but more dense. 2. The last four abdominal segments are distinctly 

 longer and broader than the corresponding segments of L. mutabilis ; this difference is 

 especially visible in the female. 3. The legs are stouter ; the hind tibiae are, on the 

 upper surface, distinctly arcuate, especially at the base ; they are straighter in the 

 other species. 4. The wings are darker brown, and the bluish reflection is more 

 distinct. 



N.B. — The synonymy with D. lugubris, Macq. (Dipt. Exot. Suppl. iv. p. 64), alleged 

 by Schiner, is very doubtful. 



2. Lastaurus mutabilis. 



Lastaurus mutabilis, Loew, Bemerk. iiber die Fam. Asiliden, p. 12 \ 



Eab. Costa Rica, Rio Sucio (Bogers) ; Panama, Volcan de Chiriqui (Champion).— 

 South Ameeica, Colombia and Venezuela 1 (Berlin Museum). 



A male, from Rio Sucio, has the abdomen, beginning with the second segment, 

 clothed with long pale yellow hairs ; the genitals beset with rufous hairs. A female 

 from Volcan de Chiriqui has the hair on the abdomen more intensely yellow. I have 

 seen Loew's types in Berlin. The species is very variable in the colouring of the hairs 

 on the abdomen. I would not call it " betrachtlich kleiner " than L. anthracinus. 



N.B. The synonymy of this species with Morimna mallophoroides, Walk. Ins. 



Saunders, p. 104, t. 4. f. 2, suspected by Schiner (Verh. z.-b. Ges. Wien, 1867, p. 373), is 

 possible ; but there are several contradictions between the diagnosis and the description, 

 and both had better be dropped. The type is not in the British Museum. 



The synonymy with D. fallax, Macq. Dipt. Exot. Suppl. iv. p. 63 (Colombia, tempe- 

 rate region), is also possible ; Macquart's description is perfectly unmeaning. 



NICOCLES. 



Nicocles, Jaennicke, Abh. Senkenb. Ges. vi. p. 354 (1867) ; Neue exot. Dipt. p. 47 (1867). 

 Pygostolus, Loew, Berl. ent. Zeit. x. p. 16 (1866); Centur. vii. no. 28; id. x. no. 24 (nomen 

 praeocc.). 



The only species described is : — 



Nicocles analis, Jaennicke, Neue exot Dipt. p. 47, t. 1. f. 13.— Mexico. 



