60 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



sides of the prothorax. These stripes in the full-grown larva 

 usually change on the ventral side to an inverted |_ , owing to 

 a shortening and rounding-out process which then takes place, 

 causing the segments to overlap slightly. In Nematodes the 

 abdominal segments are longer and more rounded and each 

 segment appears to be composed of two. The body is also 

 darker in color and more chitinous. The larvae of this genus 

 may readily be recognized by the presence of two sternal pro- 

 cesses or hooks on the prothoracic segment. The last segment 

 is dilated, chitinized, with a concave ventral depression. Species 

 of Melasis and Tharops possess this concave depression on the 

 ventral side of the last segment, but it is not chitinized nor 

 dilated. The crops of two typical representatives of these 

 respective groups were examined under a compound micro- 

 scope. That of Mclosis pectinicornis contained nothing but 

 minute fragments of wood fiber, and that of Fornax badius 

 only liquid which may have been extracted from the damp 

 wood in which they live. This comparatively small family of 

 beetles, which has been recognized by many writers as distinct, 

 has been placed by LeConte and Horn, in their classification 

 of Coleoptera, published in 1883, as a subfamily at the head of 

 the Elateridse. The only character separating them from the 

 true Elaterids is found in the insertion of the antennas at the 

 extreme front. The clicking apparatus is present, but usually 

 undeveloped, so that it is impossible for the beetle to hop into 

 the air. According to information from Mr. Schwarz, there 

 is a small species of Deltomctopus which is capable of making 

 a feeble leap, but Doctor Horn doubts the position of this 

 genus in the Eucnemidse. The eucnemids possess much better 

 characters in the larval form than in the adult. Perhaps one 

 of the best characters for separating them from the Elaterids 

 is the absence of legs or feet in the larvae. The habits and life 

 history of most of the species are also widely different from 

 those of the true Elaterids. In their immature stage they ap- 

 proach much nearer several genera in the Buprestidse, particu- 

 larly Agrilus. 



While the writer has frequently found the larvae closely 

 associated with other coleopterous and hymenopterous larvae, 

 he has seen no evidence of their possessing predatory habits. 



REFERENCE TO LITERATURE. 



It seems more convenient in this short bibliography to give 

 an outline of the subject treated by each writer. 



