110 



ENTOMOLOGY. 



legs fossorial. 



if placed on its back. The group of snapping-beetles is very ex- 

 tensive, over 3000 species being recorded; the 

 larvae are called wire-worms from their hard, slen- 

 der cylindrical bodies, and are known to live two 

 years before transforming; they are mostly her- 

 bivorous, a few larva?, however, devouring the 

 eggs of locusts. Here belongs the fire-fly of the 

 West Indies, Pyrophorus noctilucua Linn. (Fig. 

 117). 



Family Rhipiceridae. Antennas serrate in the 

 female, frequently flabellate in the males; ony- 

 chium large and hairy. Sandalus petrophya 

 Knoch. 



Family Dascyllidse. Head not constricted be- 

 hind ; eyes granulated ; mesothoracic epimera 

 reaching the coxa?. Larvae more or less aquatic. 

 Prionocyphon discoidevs Say. 

 Clavicornia. 



In this group the antennae are club- 

 shaped, while the tarsi vary in having from 



FIQ. 117. Fire-fly. -. , ? 

 Natural size. I to 5 JOllltS. 



Family Heteroceridae. Antenna? short, irregular 

 Heterocerus pallidus Say. 



Family Parnidae. Aquatic beetles, with a retrac- 

 tile head ; last joint of tarsi long, claws large. Larva? 

 aquatic, hemispherical ; that of PscpJtenus lecontei 

 Lee. lives under stones in rapid streams; the pupa 

 is formed under the larval skin which protects the 

 insect beneath like the scale of a Coccus. 



Family Georyssidae. Small, rounded, convex 

 beetles, which cover themselves with mud; coxse 

 contiguous; prosteruum semi-membranous. Oeorys- 

 sus pusillus Lee. 



Family Byrrhidae. Pill beetles; head usually re- 

 tracted under the prothorax; body oval or rounded 

 and very convex; legs retractile. Byrrhus ameri- 

 canus Lee. 



Family Derodontidae. Anterior coxae conical, transverse. Dero- 

 dontus maculalus (Mels.). 



Family Trogositidae. Antennae straight; tarsi 

 slender first joint short; living under bark or 

 in fungi, while certain species are injurious to 

 grain. Trogoxita virescens Fabr. 



Family Nitidulidae. Antenna? straight; tarsi 

 more or less dilated, first joint not short. LarvtB 

 living usually in decaying matter. Nitidula 

 bipiistul<tta Linn., Ipsfasciatus Linn. 



Family Histeridae. Body oblong and flat, or 

 round, oval, globose, or cylindrical ; antenna? 

 geniculate; tibia? usually all dilated. The 

 species are scavengers, living under bark of 

 trees, in excrements, and in carcasses. Hister interruptus Beauv. 



FIG. 118. Larva 

 of Psephetius le- 

 contei. 



FIG. 119. Ipsfasci- 

 atus. a, larva. 



