COMASTES.— PANTAEBES. 151 



Bombylius meocicanus, Wiedem. Aussereur. zweifl, Ins. i. p. 338 ; Loew, Neue 

 Beitr. iii. p. 24. — United States, Mexico. 



helvus, Wiedem. loc. cit. p. 336. — Mexico. 



ravus, Loew, Centur. iv. no. 50. — Mexico, Matamoras. 



COMASTES. 



Comastes, O. Sacken, Western Diptera, p. 256 (1877) . 

 Heterostylum, Macquart, Dipt. Exot. Suppl. iii. p. 35 (1848) . 



In the * Western Diptera ' I have described the female only of this genus. The head 

 of the male is much less broad than that of the female and much narrower than the 

 thorax ; my description of the thorax must therefore be modified in that sense. The 

 eyes are almost in contact above the frontal triangle; a magnifying-glass shows, 

 however, a linear interval between them. 



Since establishing Comastes I have discovered a passage in Loew's writings which I 

 had overlooked before, and in which he foreshadowed its introduction. In the Neue 

 Beitr. iii. p. 29, he notices the peculiarities of Bombylius basilaris, Wiedem., and 

 B. ferrugineus, Fabr., and says " that both would deserve to form the nucleus of a 

 separate genus." As a character of this future genus he notices the emargination of 

 the occipital orbit of the eyes, which is larger than in Bombylius. 



In my catalogue of the N. Am. Dipt. 1878 (Additions &c. p. 267), I have shown 

 that Heterostylum, Macq., is the same as Comastes. The principal character assigned 

 to it by Macquart, and from which he derived the name of the genus, is the supposed 

 pubescence of the third antennal joint. This has no existence in reality, for Macquart 

 mistook dust for a pubescence, and his name must therefore be cancelled. I saw the 

 type in Mr. Bigot's collection. 



1. Comastes rofcustus. 



Comastes robustus, O. Sacken, Western Dipt. p. 256. 



Bab. Noeth America, Waco, Texas {Bel/rage), Dallas (Boll).— Mexico (coll. Bel- 

 lardi), Presidio (Forrer). 



I have before me a specimen from Presidio, and a pair, also from Mexico, in 

 Prof. Bellardi's collection; all three are entirely abraded. Nevertheless I have no 

 reason to doubt that they are correctly determined as C. robustus. 



PANTAEBES. 



Pantarbes, O. Sacken, Western Dipt. p. 254 (1877) . 



Two new species of this genus enable me to correct and to complete the generic 

 description. I reproduce it from my former publication with the necessary changes. 



