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 noctUucus Linn. (Fig. 

 117). 



Family Rhipiceridae. — Antenna? serrate in the 

 female, frequently flabellate in the males; ony- 

 chium large and hairy. Sandalus petrophya 

 Knoch. 



Family Dascyllidae. — Head not constricted be- 

 hind ; eyes granulated ; mesothoracic epimera 

 reaching the coxa?. Larva? more or less aquatic. 

 Prionocyplwn discoideus Say. 



Clavicornia. 

 In this group the antennae are club- 

 shaped, while the tarsi vary in having from 



Fig. 117.— Fire-fly. A , K • • .„ 

 Natural size. 1 to 5 joints. 



Family Heteroceridae. — Antenna? short, irregular; 

 Heterocerus pallidus Say. 



Family Parnidse. — Aquatic beetles, with a retrac- 

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

 aquatic, hemispherical ; that of Psephenus 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; coxa 1 

 contiguous; presternum semi -membranous. Georys- 

 sus pusillm Lee. 



Family Byrrhidae.— Pill beetles; head usually re- 

 tracted under the prothorax; body oval or rounded 

 and very convex; legs retractile. Byrrhus ameri- 

 cam.ua Lee. 



Family Derodontidae. — Anterior coxa? conical, transverse 

 dontus moculatm (Mels.). 



Family Trogositidae. — Antenna? straight; tarsi 

 slender first joint short; living under bark or 

 in fungi, while certain species are injurious to 

 grain. TYogosita oireseens Fabr. 



Family Nitidulidae. — Antenna' straight; tarsi 

 more or less dilated, tirst joint not short. Larva? 

 living usually in decaying matter. Nitidula 

 bipiistulata Linn., Zpsfasciatm 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. Sister interrupt as Beauv. 



Fig. 118.— Larva 

 of Psephenus le- 

 contei. 



Dero- 



Fig. 1 1 9.— Ips fasci- 

 atus. a, larva. 



