LARVAL FORMS OF COLEOPTERA 



nally bidoiitate or tridentate, alternating in some dimorphic 



species -witli rather short and terminally truncate ones) 



Drxiopidae - Helminae (Dryops, 

 Helmis, Limnius, Ancyronyx, 

 etc.) (pis. 71 K-Z, 73 A-E) 



K. CANTHAROIDEA 



Key to Families and Subfamilies 



1. Ninth abdominal segment posteriorly with unpaired pointed 



prolongation, or paired urogomphi ; bod}^ with featherlike 

 or spinose processes. (Nasale posteriorly limited by a faint 

 line ; epicranial halves meeting ventrally ; subf acial sinus of 

 epicranium for the reception of the ventral mouthparts pres- 

 ent; mandibles inserted well apart, falciform, canaliculate 



and without retinaculum; galea one-jointed) 2 



Ninth abdominal segment without unpaired posterior pro- 

 longation and without paired urogomphi ; body without con- 

 spicuous processes 3 



2. Frontal sutures present; cardo present; gular suture long; 



second antennal joint enlarged ; ninth abdominal segment 

 posteriorly tapering into a long, spinose prolongation ; body 

 dorsally with spinose warts, laterally with featherlike pro- 

 longations Brachypsectridae Blair^'' ( pis. 



74 A-F, 75 A) 

 Frontal sutures absent; cardo absent or completely mem- 

 branous ; gular area very short ; second antennal joint not 

 enlarged ; ninth abdominal segment with paired urogomphi ; 

 body with spinose, dorsal, or dorsal and lateral, prolonga- 

 tions. (Spiracles in small separate epipleural projections or 



plates) Drilidae (Drilns and Silasia)'^° 



(pis. 74, G-N, 75 B-E, 77 A) 

 ■'^ Blair, K. Ct., Brachypsectra, Lee. — The Solution of an Ento- 

 mological Enigma, Trans. Ent. Soc. London, June 30, 1930, vol. 78, 

 pp. 45-50, one plate. 



The family Brachypsectridae, Blair, is considered a valid family 

 according to the characters of the larva but, following H. S. Bar- 

 ber, it is here placed in the series Cantharoidea. It has close affin- 

 ities to the larvae of Drilus and Silasia. The suggestion of Blair to 

 join it with the Elateroidea has not been followed even if it un- 

 questionably has close affinities with this latter series and partic- 

 ularly with the subfamily Cardiophorinae. In agreement with 

 Blair, the usual conception of Brachypsectra as dascilloid is here 

 disregarded. 



'^° Drilus has polymorphic metamorphosis, the last instar of this 

 snail-eating larva being maggotlike with a white, soft body and 



46 



