381 



GENERIC CHARACTERS 



Larva. — Head large and broad; maxillae with a distinct incision 

 in their outer margin near the middle ; maxillary palpi distinct ; surface 

 hairs on head long. Thoracic segments, as figured by Brauer for 

 Laphria, longer than the abdominal, the latter more or less distinctly 

 divided transversely, the anterior portion with a circle of 6 wart-like 

 pseudopods ; apical segment without chitinized teeth and shorter than 

 subapical in young larva, longer in mature larva, and with a chitin- 

 ized upper posterior margin bearing 3 teeth. 



Pupa. — Distinguished from other asilid pupae by the armature of 

 the head, the antennal sheaths each being quadrispinose. 



Imago. — Robust species, usually with conspicuous silky hairs on 

 abdomen. 



HABITS OE EARVAE 



The larvae live in decaying wood, usually in standing trees, and 

 prey upon Coleoptera and other wood-boring insects. The very strong 

 cephalic armature of the pupa serves to cut a way' to the surface in 

 time for the emergence of the imago, even in trees whose wood is 

 hard. 



HABITS OE IMAGINES 



The imagines have a preference for sitting in the sunshine on ex- 

 posed tree-trunks and fence-posts. They are predaceous, but occa- 

 sionally are found on flowers. They attack large Diptera and Hy- 

 menoptera, victimizing even wasps and hive-bees. 



Dasyleis sp. ? 



Larva (immature). — Length, 10 mm. Head (PI. LIV, Fig. 12) 

 broad and flat, maxillary incision of moderate depth ; maxillary palpi 

 slender, 2-jointed; mandibles short, not surpassing basal third of 

 maxillae; dorsal posterior rod about 5 times as long as broad, of al- 

 most uniform thickness, slightly arcuate transversely; the paired 

 lower rods slender. First thoracic segment much longer than the 

 others. Each dorsal abdominal segment except the apical 2 with 4 

 pselidopod-like protuberances in a transverse series, the same ventral 

 segments each with 2 such protuberances; transverse division of seg- 

 ments not distinct ; apical segment rounded, no chitinized margin evi- 

 dent. 



Described from a specimen obtained in woods at Urbana, 111., 

 April 12, 1892 (McElfresh and Snow). 



