COLLECTION OF ARTICULATED ANIMALS. 4^7 



varied curves which they form on the surface 

 of the water. Next to these aquatic insects 

 comes another family of coleoptera, equally car- 

 nivorous with the last, but confining themselves 

 to the land ; it is composed of the genera ca- 

 rabus, Lin., manticora, Fabr., cicmdela, Lin., 

 scarites, Fabr., and elaphrus, Fabr. Many spe- 

 cies of them, particularly of the first mentioned 

 genera, which are remarkable for their size 

 as well as their lustre and for the symmetrical 

 elevation of their wing-sheaths, have a foetid 

 smell, and when caught sometimes emit an acri- 

 monious and corrosive fluid. The carabus an- 

 ratus, Lin. (n 9), common in our fields, and the 

 c.sycophanta(n 24), have the wing-sheaths of a 

 very brilliant golden green colour; the latter 

 feeds as well as its larva upon caterpillars, and 

 especially upon those of the oak. There are 

 others of the same genus (n os 102 and 108) which 

 have a very extraordinary method of attempting 

 to escape from their enemies. They cause a caustic 

 liquor of an ammoniacal smell, which imme- 

 diately dissipates into vapour, to proceed re- 

 peatedly and with an explosion from the hinder 

 extremity of their body; for this reason they 

 have been named crackers, pistols, etc. The 

 manticora maocillosa, Fabr., (n os i and 2,) comes 

 from southern Africa; it is one of the largest in- 



3o. 



