ONCODOCERA. 141 



ONCODOCERA. 



Ogcodocera, Macquart, Dipt. Exot. ii. 1, p. 83, t. 15. f. 1 (1840). 

 Oncodocera, as amended by later writers. 



In introducing the genera Anisotamia (op. cit. p. 81, t. 14. f. 2) and Oncodocera 

 Macquart correctly denned their differences from Anthrax, but he did not seem to be 

 aware that they are much more closely allied to Lomatia, and that, in this respect, his 

 definition was wanting. Loew (Sudafr. Dipt. p. 205) strongly suspects that the Ani- 

 sotamia centralis, Macq., from the Cape, is the same as Lomatia pictipennis, Wiedem. 

 The Anisotamia eximia from Mexico (syn. Anthrax valida^ "Wiedem.) was added much 

 later, in Macquart's Suppl. iv. p. 115. Whether the latter is a true Anisotamia in 

 Macquart's original meaning I cannot tell, but it seems to me that there is very little 

 reason for not placing it in the same genus with Oncodocera dimidiata, Macq. (synon. of 

 Mulio leucoprocta, Wiedem.). In my Catalogue of N. Am. Diptera, 1878, p. 90, I 

 have placed both species in the genus Oncodocera. 



Oncodocera valida has the antennae approximate at the base, the first joint short, the 

 second round, the third subulate (awl-shaped) and with a microscopic, indistinct 

 appendage at the tip ; proboscis withdrawn within the mouth ; frontal triangle rather 

 large ; eyes separated on the vertex in the female, contiguous in the male for a rather 

 short interval ; ocellar triangle (in the male) small and narrow, wedged in between the 

 eyes. Abdomen beset with very long, bushy hairs, especially on the sides; with 

 seven distinct segments; the seventh broader in the female than in the male ; a small 

 eighth segment, withdrawn within the seventh, is distinctly visible in the male ; the 

 forceps concealed within the eighth segment ; the female shows not the usual coronet 

 of spinules but that circle of concentric hairs which is visible in the same sex of 

 Aphcebantus, Triodites, and the allied genera. The pulvilli distinct. Front tibiae 

 beset with spinules ; hind tibiae with a fringe of hairs on the upperside, not unlike 

 that of some Tabani. Wings : bifurcation of the second and third veins close to the 

 origin of the second, and very far from the small cross-vein ; the latter is oblique 

 and considerably beyond the middle of the discal cell ; anal cell closed ; first posterior 

 cell closed, sometimes, however, narrowly open ; the end of the auxiliary vein very 

 near the end of the first longitudinal vein ; contact of the discal and fourth posterior 

 cells broad. 



Oncodocera leucoprocta shares the same characters, and the differences must be con- 

 sidered as having a merely specific value ; the third joint of the antennae is a little 

 broader at the base, and therefore like a flattened cone or triangle (the figure in 

 Macquart is very incorrect) ; the hind tibiae have no fringe of hairs, but in both sexes 

 only scattered spinules ; the first posterior cell is open. 



The differences between Lomatia and Oncodocera are considerable : in Lomatia the 

 eyes of the male are not contiguous on the vertex, but separated by a narrow interval ; 



