ART. 17. LARVAE OF HOLARCTIC TIGER-BEETLES HAMILTON. 15 



For each species there has been given the name of the collector, a 

 statement as to whether the larvae were reared or not reared, and the 

 place Avhere the larvae are deposited. Species marked " reared " 

 have had the larvae reared for determination, but the cast skins were 

 not saved and comparisons were not made with the larvae used in 

 the descriptions. Species marked '' not reared " have not had the 

 larvae reared for determination, but in most instances all the other 

 species of the community were reared or their habits were so re- 

 stricted and characteristic that there was but little doubt they were 

 larvae of adults cau<jht in the habitat. Several unknown larvae with 

 suggested determinations have been included. Their names have 

 been derived through a study of the distribution of the adults and a 

 comparison of the larval structures and habitats with known 

 material. 



Family CICINDELIDAE. 



Larvae of medium length, cylindrical ; head and pronotum strong- 

 ly chitinized, wider than the remainder of the body and inclined 

 ventro-cephalad ; head concave on the dorsal aspect, strongly convex 

 on the ventral; clypeus and labrum fused with the frons; ocelli, four 

 or six on each side of the head, ocelli 1 and 2 larger than the others, 

 ocelli 5 and 6 sometimes absent; antenna four-segmented; mandible 

 sickle-shaped with a prominent tooth on the middle of the mesal 

 margin, inclined dorso-cephaled at an angle of about 45 degrees; 

 maxilla with the ventral sclerite of the carclo more or less tri- 

 angular, stipes considerably longer than wide, galea two-segmented, 

 proximal segment of the galea and the palpifer fused; maxillary 

 palpus two or three segmented; labial palpus two-segmented; pro- 

 notum large, shield shaped, heavily chitinized, and fitting close 

 against the caudal margin of the head; legs, long, tarsus usually 

 with two movable claws, the cephalic claw longer than the caudal; 

 abdomen with ten distinct segments, fifth segment with a dorsal 

 protuberance bearing two or three pairs of hooks; cerci wanting; 

 spiracles lateral, annular and present on the mesothorax and first 

 eight abdominal segments. 



The family characters of the larvae have been determined from 

 examination of specimens representing the four genera occurring in 

 the United States, two European genera, and several tropical genera 

 which have not been definitely determined, the larvae of which live 

 in burrows in twigs. It is in those larvae living in burrows in twigs 

 that the tarsal claws are wanting as distinctly movable claws. In the 

 wood burrowing larvae the tarsus is produced into two blunt pro- 

 jections serving as claws. I have not examined enough species to 

 definitely state whether this is a generic or specific character. 



