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ART. XXVII. — An attempt to classify the Longicorn Coleoptera of the 'part of 

 America North of Mexico. By John L. LeConte, M. D. 



Works cited. Hald., Haldeman in Transactions of the American Philosophical 



Society. Vol. X. 

 Harris, Transactions of the Hartford Society of N. H. 

 Say, Boston Journal and Journal of the Academy of Natural Sciences, 



Philadelphia. 

 Nm. Ent. Mag., Newman in Entomological Magazine. 

 FoRSTER, Centuria Insectonim. 



Dej. Cat., Catalogue de la collection de M. LeComte Dejean. 

 Serville in Annales de la Societe Entomologique. 

 Fabr., Fabricius. 

 Ol,, Olivier. 



Kb., N. G, Kirby Fauna Boreali Americanse. Vol. IV. 

 Randall, Boston Journal of Natural History. 

 Germ., Germar Insecta Nova. 

 Lap., Laporte et Gory Monographie du genre Clytus. 



PART I. CONTAINING THE CERAMBYCL 



In the present essay I have made many innovations in the former arrangements of 

 these insects. These will be found more obvious in the first group, the LepturidcB. 

 The indistinct characters of the genera as left by Serville and Mulsant, have long 

 rendered some other classification necessary ; since being founded on very slight and 

 arbitary differences of form, they unite together many species which, agreeing in 

 certain trivial circumstances, differ widely in general appearance. Such is the genus 

 Pachyta, which on account of its heterogeneous nature I have been compelled to 

 suppress altogether. Such again is Grammoptera, which was established on Lepturce 

 with linear elytra. If a comparison of a large number of species be made, this 

 character is found to be entirely fallacious, so that however clear the mathematical 

 distinction may be between lines that are and are not parallel, it will be seen that in 

 nature this distinction cannot obtain. The proportions and form of the elytra vary 

 in all the genera, and it would be quite as rational to separate into distinct genera, 

 those with incised and those with dehiscent elytra. 



Although these characters are thus shown to be mere specific marks, we may 

 derive much aid from them in forming sections in those genera which contain many 

 species ; they may thus be made to alleviate the labor of identifying species : and in 



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