LAEVAL FORMS OF COLEOPTERA 



SUBORDERS 



The systematic characters defining the larvae of the three sub- 

 orders, Avhose relative phylogenetic positions now have been dis- 

 cussed, are as follows : 



A. Archostemata. Legs six-jointed with distinct tarsus and 



one or two distinct claws ;'* always a mandible possessing 

 a strong molar part, and with hypopharyngeal and parag- 

 nathal structures fused with prementum into a strong, 

 hard unit. 



B. Adepkaga. Legs six-jointed with a well defined tarsal joint 



and one or two distinct, movable claws f mandible lacking 

 a molar part ; hypopharynx never united with prementum 

 into a strong, hard unit. 



C. Polyphaga. Legs five-jointed, the tarsal joint fused with a 



single claw into a tarsungulus; or less than five-jointed; 

 or no legs present."^ 



^Except in the instars of Mio'onniltJius, which are legless or 

 have three-jointed legs. 



* All, or some , of the larval instars of the carabid species Brachi- 

 nus janfhinipennis Dej. and Lehia scopularis Dej. are adapted to an 

 ectoparasitic life to the extent that it is impossible to place them 

 systematically by a mere examination of the body structures. In 

 the series Paussoidea (p. 24), of which, however, only the last lar- 

 val instar is known, the legs are three-jointed, but this myrmecoph- 

 ilous larva can be recognized by the unique development of the 

 eighth abdominal segment into a large, terminal, glandular disk. 

 Tibia and tarsus fused in a few cicindelid genera (p. 18). 



^ Several larvae as the staphylinid genera Philonfhus and Ble- 

 dius, the first instar of the staphylinid species Aleochara hilineata 

 Gyllenhal, Euplectus, some genera of Histeridae, and the ceram- 

 bycid genus Nothorhina have the tarsungulus divided by a faint 

 suture into a proximal and distal portion which possibly correspond 

 respectively to tarsus and claw. In several of the Bostrichoidea, 

 particularly in Ptilineiirus marmoraius Reitter, the tarsungulus has 

 not the usual character of a claw but of a long, pointed, upward 

 curved joint carrying many, strong, spinelike setae, the tarsal por- 

 tion of the tarsungulus here being predominant. 



