840 FAMILY XIJ. MArjACITIID/i;. 



lips. From liio rjanipyi'ida' th<'.\' urc disl inyiiislKnl cliietly by liav- 

 ing the aiitennte inserted upon the front at the sides, generally be- 

 fore the eyes ; by the presence of a separate piece between the labrum 

 and the front and by the fourth joint of the tarsi not being bilolied. 

 The great majority of our Indiana species also have the power of 

 protruding from the sides of the abdomen a number of soft, orange- 

 colored vesicles which are supposed to be scent organs used in 

 defense. 



In addition to the characters nHMitioned. the JMalachiida? have 

 the iuentum si'iail. (juadrate and li"ni-iik-e ; antenna^ 11-jointed, 

 usually serrate and uftcn curifnisly knotted in the male; head ex- 

 serted and prolongcl into a short, broad l)eak; elytra usually en- 

 tire, sometimes slightly al)breviated ; al)domen with six free ventral 

 segments; proslcrnum slioi't, not extendiiig l)et\veen tlie front coxa', 

 whicli are large, conical, contiguous, with distinct trochantins, the 

 coxal cavities hirge, transverse, open lichind; tarsi 5-jointed, fili- 

 form; clav.s usually with a larac menibi-anous apjyendagc between 

 them. 



The larvu' of the ^lalachiida' are. so far as known, carnivorous. 

 The mature insects occur on flowers or heritage, some only in low. 

 moist places, and are said to feed on insect eggs, larvte and small, 

 soft-bodied insects, so that on the whole they may be classed as 

 beneficial. 



The principal litei'ature treating of the genera occurring in 

 Indiana is as follows: 



LeCoidc. — ''Catalogue of the Melyrides of the United States, 

 with Descriptions of New Species." in Proc. Phil. Acad. 

 Sci., VI, 1852, 168-171. 



Horn. — "Synopsis of the Genus Collops," in Trans. Amer. 

 Entom. Soc, III, 1870. 79-84. 



TIoDi. — "Synopsis of the Malachiida- of the United States." //( 

 Trans. Amer. Entom. Soc. IV. US72. 109-127. 



Casey. — "Synopsis of the Melyrida^ of North America." in. Ann. 

 N. Y. Acad. Sci., VIII, 1895. 456-600. 



About 140 si)ecies. distributed among 20 genera, are listed by 

 IFenshaw from the Unit<-d States, most of them inhabiting the 

 i-egion west of the Rocky Mountains. 



KEY TO THE INDIANA GENERA OF ArALACHIID^. 



a. Sides of body with oxteiisiI)le vesicles, tlie front pair proceeding from a 

 flssnre heneatli tlic front an,!,'l<'s of tlic tliorax : last joint of tarsi with 

 two meniliranons a])pend:iges l»eno;itli tlic claws. 

 J). Antenna' apjiarently ]0-.jointed. I. (loi.i-ors. 



