PARASITIC-BEETLES. 113 



to refer to some of tlie most coimnou instances of this cliange in the 

 introductory part of this work, and the same is strikingly dhistrated 

 in the history of the prtjseut tribe, in which the same species is often 

 parasitic in its hirva state, wliilst it feeds upon the flowers or foliage of 

 plants in its perfect or imago state. 



The following is a table of the families of the Traehelides : 

 A. Constriction of the neck gradual and slight ; anterior coxal cavities closed behind.* 



Size medium LAGRiin.K. 



A A. Neck distinct and al)rupt; anterior coxal cavities always open behind. 



B. Thorax with a lateral margin ; abdomen usually tapering to a long point; hind 



legs long and Hat. Size small MoRDELLiDiE. 



13 IJ. Tliorax rounded at tlie sides; abdomen not pointed. 



C. Tarsal claws deeply cleft. Size large or medium MELOiD-t:. 



("C. Tarsal claws entire. 



D. Tliorax narrower behind than the elytra. 

 E. Antennse almost always filiform and simple. Size very small. Anthicid^. 

 E E. Antennaj usually' branched in the male, serrate in the female. Size 



medium or small PYiiocnROii)^. 



D 1). Thorax as wide behind as the elytra. Size small HhipipiiohiDxE. 



A A A. AVilhout visible neck — structure very abnormal. Size very small. Styloiubjj:. 



Family XLII. LAGRIID^. 



This family is comprised of a small number of medium sized beetles, 

 which furnish a connecting link between the Trachelides and the Teue- 

 brionida' ; having an imi)erfect neck, and being rather soft and llexi- 

 ble like the former, but having the anterior coxal cavities closed behind, 

 like the latter. Mr. Westwood states that he has found the larva of the 

 European />((</rm /<//•/</. on white thorn hedges; and Lyonet mentions 

 having di^scovered the same under dead leaves upon the ground. 



There are but five N. A. species of this family. The Lagria (Ar- 

 thromaeraj (vnea, Say, is an elongate brassy-black beetle, nearly half an 

 inch in length, and easily recognized by the remarkably elongated ter- 

 minal joint of the antenna', which is as long as the four preceding 

 joints taken together. 



Family XLIII. MORDELLID^. 



This family contains a considerable number of small beetles, rarely 

 more, and usually less than a (luaiter of an inch in length, and distin- 

 guished by their elliptical and arched form, the head being bent dowTi 



* Thp stato of the antorior eoxal cavities as r«»ai)pcts tUoir being olo.soil or open l)ebin<l, is a charac- 

 ter of considerable importance in chissifying the Coleoptora, esjjecially the neterouiera. The coxal 

 cavities are the hollows in the sternum or breast plate in which the legs are inserted. The anterior cav- 

 ities are sometimes wholly surrouuiloil by the crust of the stornnm, when they are said to bo closed ; 

 in other cases there is a deficiency of the sternum directly behind the anterior coxu:, which is filled by 

 membrane, and the cavity is then said to be open. 



—15 



