THE NECROPIIAGA, OR CLAVICORNES. 101 



holes made in the wood of fir-trees by certain species of 

 Xylophaga, and lays eggs in their galleries; its larvae 

 feeding on those of the latter insects, and, being of 

 slower development, taking more than a year to trans- 

 form. 



The females in this genus, as in Cryptarcha, have the 

 elytra rather pointed at the apex. 



The species of Rhizophagus appear from the differences 

 above mentioned to be very aberrant from the others of 

 this sub-family ; the cavities into which their coxae fit are, 

 moreover, completely closed behind, and the male has 

 a small additional segment to the abdomen. They are 

 small, linear insects ; chiefly found under bark, though 

 some occur in ants' nests, and others in bones, etc. The 

 larva appears to be like that of Soronia grisea above 

 described, in miniature. M. Ferris states that he has 

 observed the larvae of R. depressus to have similar habits 

 to those of Ips ferrugineus ; and that more than once he 

 has seen two or three of the larvae with half their bodies 

 plunged into the larvae or pupae of Hylesinus or Hylastes, 

 devouring them. He has also taken home the larvae of 

 both Rhizophagus and Hylesinus, and often not one of 

 the latter escaped being eaten. 



The Rhizophagus appeared to turn to pupa in the 

 ground, and not under the bark. 



The TROGOSITID.E have two lobes to the maxillae; 

 the tarsi five-jointed, simple, and with the first joint 

 very small; and the elytra covering the abdomen. The 

 apical joint of the tarsi is also very long, and has between 

 its claws a small and slender styliform lobe, terminated 

 by two diverging bristles. The tibiae are unspined on 

 the outer side, but have a more or less hooked spur at 

 the apex of the anterior pair. Nemosoma elongata, a 



