INTRODUCTION. 9 



probably too girat for our country, where vast tracts are covered 

 with forests, aiul the other original vegetabU^ races still hold 

 possession of the soil. There are above 1200 flowering plants 

 in Massachusetts, and it will be within bounds to estimate the 

 species of insects at 4800, or in the proportion of four to one 

 plant. To facilitate the study of such an immense number, 

 some kind of classification is necessary; it will be useful to 

 adopt one, even in describing the few species now before us. 

 The basis of this classification is founded upon the structure 

 of the mouth, in the adult state, the number and nature of the 

 wings, and the transformations. The first great divisions are 

 called orders, of which the following seven are very generally 

 adopted by naturalists. 



1. — CoLEOPTERA (Beetles). Insects with jaws, two thick 

 wing-covers meeting in a straiglit line on the top of the back, 

 and two filmy wings, which are folded transversely. Trans- 

 formation complete. Larvae, called grubs, generally provided 

 with six true legs, and sometimes also with a terminal prop-leg; 

 more rarely without legs. Pupa with the wings and the legs 

 distinct and unconfined. 



Many of these insects, particularly in the larva state, are very injuri- 

 ous to vegetation. The tiger-beetles {CicindeJadcs*), the predaceo-js 

 ground-beetles (Carfli/dfc), the diving-beetles {Dytiscidcr), the lady-birds 

 (Coccinellada;), and some others, are eminently serviceable by preying 

 upon caterpillars, planl-lice, and other noxious or destructive insects. 

 The water-lovers {Hydrophilidcc), rove-beetles (SlaphylinidcE), carrion- 

 beetles (Si'/p/tctrfffi), skin- beetles (Der?nesladce, Bi/rrhidce, and Trogida>), 

 bone-beetles (some of the NitiduIadcE and Cleridcp), and various kinds 

 of dung-beetles [Sphcpridiadce, Histeridce, Geotrupidccf, CoprididcBf, 

 and Aphodiadcef) , and clocks (PimeUadcr- and Blaplidce),dLC\. the useful 

 part of scavengers, by removing carrion, dung, and other filth, upon 

 which alone they and their larvfc subsist. Many Coleoptera (some 

 StaphylinidcE and NiiiduJadce, Diaperididce, some Serropalpidce, Myce- 



* See the Catalogue of Insects appended to Professor Hitchcock's Report on 

 the Geology, Mineralogy, Botany, and Zoology of Massachusetts. 2d edit. Svo. 

 Amherst. 1835. 



t AH the Scarabajidae of my Catalogue, from Ateuchus to Geotnipes inclusive, 

 to which may be added many included in the genus Scardbceus, 



2 



