76 GEO. H. HORN, M. D. 



Synopsis or the DAl§>CYL.L.IDi£ of the United States. 



BY GEORGE H. HORN, M. D. 



Since the publication of the synopsis of a portion of this family 

 by Dr. Leconte, (Proc. Acad. 1853, pp. 350 — 357), no attention had 

 been given it until the appearance of the " Classification" (pp. 177 — • 

 182), in which the genera only are considered. This may be ac- 

 counted for by the very uninteresting nature of the greater number 

 of the smaller forms and the difficulty in determining the precise 

 limits of species. 



It has been more especially the object of the present essay to deal 

 with the species, the genera being already sufficiently well defined in 

 the books. The systematic arrangement of the tribes and genera here 

 adopted, is practically that proposed by Dr. Leconte with some minor 

 difi"erences in the tables, having for their object either the introduction 

 of new genera or for the illustration of certain lines of affinity which 

 are mentioned in their proper places. 



The characters of the family have already been fully made known 

 in general works and it is not necessary to repeat them here. It is 

 necessary to add to the generalities the presence of bifid claws in the 

 tribe Eubriini and the presence of membranous appendages to the 

 claws of Placonyclia. 



That there exists a very close relationship between this family 

 and the Rhipiceridse must be admitted, the only character which 

 seems to separate them is found in the prominent middle coxae 

 of the Rhipiceridae, and if we admit the genus Brachi/psectra J^ec. 

 (Trans. Am. Ent. Soc. 1874, p. 55), this character also fails as 

 neither the anterior nor middle coxjb are prominent, nor is there 

 an anterior trochantin as in all Rhipiceridas. This need not con- 

 cern us here as a further study of the genus will place it nearer 

 the true Elateridae. 



The absence of an onycliium is by no means constant in the pres- 

 ent family and that organ is as well developed in Stenocolus Lee. 

 (Lichas Westw.), as in the majority of Rhipiceridae. The form of 

 the head and especially that of the mandibles in Sicnocolua, Dascyllus 

 and Anorus, strikingly resemble those of Sandalus, etc. 



While the afiinities of the genera in one portion of the family are 

 in one direction there is a certain resemblance shown between the 



