373 



far as they go. A comparison of specimens would be necessary to 

 discover specific distinctions. 



Family APIOCBRIDAB 



The species of this family with two exceptions are unknown to 

 me. They are, as far as known, confined to the south-western states 

 and Mexico. There is a diversity of opinion regarding their super- 

 family location, and I have placed the family in Asiloidea with con- 

 siderable hesitation, as the flies appear to resemble the family 

 Nemestrinidae to some extent. A knowledge of the larval and pupal 

 characters would undoubtedly throw much light upon their relation- 

 ships. 



Family ASILIDAB 



FAMILY CHARACTERS 



Larva. — The structure of the segment which bears the posterior 

 spiracles is generally the most readily appreciable character for the 

 recognition of the larvae of this family, as it is sharply differentiated 

 from the adjoining segments in most of the known forms, being occa- 

 sionally very short and appearing in the form of a slightly depressed 

 strip. Leptogaster flavipes, however, has this segment at least as long 

 as the last one and not appreciably depressed. There is some varia- 

 tion in the form of the head in the different genera, but as far as I 

 have seen they all present much the same general structure, the 

 maxillae being particularly well developed, flattened dorso-ventrally 

 and more or less triangular in shape. The thoracic segments are each 

 armed with a single long hair on the middle of the latero-ventral line, 

 and the anterior spiracle is well developed. The abdominal segments 

 are well differentiated in those genera that I have examined, and ex- 

 cept the apical one bare. The lateral spiracles on metathorax and ab- 

 domen are small but distinct. Laphria, as figured by Brauer, presents 

 an exception to the general rule obtaining throughout the known mem- 

 bers of the family in having the first 6 abdominal segments sub- 

 divided and the anterior portion of each with 6 wart-like protuber- 

 ances — 2 on dorsum and 4 on venter. 



Pupa-. — With the exception of Leptogaster flavipes^ll of the pupae 

 known to me have the antennal sheath with 3 to 5 stout thorns (re- 

 ferred to in this paper as the "lateral cephalic thorns"), and the dor- 

 sal abdominal armature consisting of stout thorns in transverse series, 

 the sizes alternating large and small on the central portion of each se- 

 ries. In one of my published papers on the pupae of these groups I 



