Vol. xxvii] ENTOMOLOGICAL xK\vs. 439 



Dipterological Notes. II. 



A Study of the Lateralis-Group of the Bombyliid Genus Villa 

 (Anthrax of Authors, in Part). 



By E. T. CRESSON, JR., Academy of Natural Sciences, Phila- 

 delphia, Pa. 



In working over the collection at the Academy of Natural 

 Sciences of Philadelphia, this group of the Bombyliidae gave 

 me some trouble. It includes Say's species Antlira.r latcralis 

 and alternate, and the original descriptions of these are so 

 nearly alike in specific value that it is difficult to associate speci- 

 mens with them satisfactorily. The next author to attempt to 

 describe the two species as distinct is Coquillett,* and his 

 attempt also does not seem to work out very well. 



Before me is a series of specimens evidently belonging to this 

 group, and to me it certainly contains two distinct species. Now 

 as to which is latcralis and which is alternata is difficult to de- 

 termine from Say's descriptions, with the possible exception 

 of the sizes given. However, the two species in this series are 

 easily separated by a character which has apparently been 

 overlooked, or at least does not seem to have been mentioned, 

 to my knowledge, in any descripiton of latcralis or alternata. 

 That is the form of the vestiture of the lateral margins of the 

 last four abdominal segments. In my series I can recognize 

 two, with a doubtful third, distinct species from North Ameri- 

 ca, belonging to this group, but there seems to be a number of 

 possible varieties. 



This group may be characterized as follows : 



lateralis-group. 



Third antennal joint onion-shaped with styliform apex. Pace con- 

 vex, cpistoma not produced conically. Abdomen with black toincntuin 

 on dorsinn; lateral pile of first and second segments pale; of third 

 black. I'orc tarsal claws minute. 



The name Villa Lioy (1864), genotype Anthrax abbadon 

 Fab. is congeneric with Hemipenthes Loew (1869), genotype 



Mu sea inorio Linn. 



Villa lateralis. 



1823. Anthrax latcralis Say, Journ. Acad. Nat. Sci. Phila., iii, 42. 

 1887. Hyalanthrax latcralis Osten Sacken, Biol. Cent. Amer., i, 135. 

 *i887. TransTAmr Ent. Soc., xiv, 166. 



