226 



LECONTE— SYNOPSIS OF PTEROSTICHUS. 



consider my group as constituting a single genus, corresponding with his Cyclo- 

 trachelus, I have felt myself compelled to adopt a new name, leaving to those who 

 may wish still farther to divide the genus, the power of restoring Cyclotrachelus to 

 the particular set of species for which it was intended. 



The third genus is precisely equivalent to Chaudoir's genus Megalostylus* which 

 name was however previously employed by Schonherr for a genus of Curculionites. 



The two last genera, Lophoglossus Lee. and Holciophorus Lee, have been sepa- 

 rated on account of the structure of the ligula, which, instead of being flat, or slightly 

 convex, as in the other genera of this group, is strongly carinate; as in the genera 

 above referred to, these differences are accompanied by peculiar sexual structures in 

 the male, so that throughout this group the males have much more generic character 

 than the females, and it is indeed the permanency of these sexual characters through- 

 out closely allied species that gives the first distinct clue towards a dismemberment of 

 the group. 



In establishing the diagnoses of these genera, we are, however, compelled to neglect 

 these sexual characters, as they are applicable to the males alone. But having once 

 recognised by their aid the existence of natural genera, and having sketched out their 

 limits, we may then make use of characters of less importance to define these genera. 

 Thus I have been compelled to rely upon dorsal punctures for the generic character; 

 and although there is such a gradual transition from those with several dorsal punc- 

 tures, to those with none at all, yet it is singular that those species with single dorsal 

 punctures form well defined genera, not merging at all into the others. 



Our genera may be separated by the following synoptic table : 



B. 



Antennae articulis basalibus cylindricis 



Elytra unipunctata : paraplcurae breves. 

 Elytra impunctata vel pluripunctata. 



Ligula plana, vel paulo convexa. 

 Ligula carinata, parapleurae longae. 

 Ligula carinata, parapleurae breves. 

 Elytra unipunctata ; parapleurae elongatae. 

 Antennas articulis basalibus carinatis. 



evabthrtjs. 



Pterostichus. 

 Lophoglossus. 

 HoLCiopnoRus. 



LOXANDRUS. 

 POECILUS. 



These genera form a little group in the family of the Pterostichini, distinguished 

 by having the mentum strongly toothed, the tooth usually bifid and concave ; the 

 ligula truncate with linear paraglossse; the palpi slender and cylindrical, the last joint 

 truncate, never longer than the preceding, and usually a little shorter. The anterior 

 angles of the mentum are sometimes acute and sometimes rounded, but for systematic 

 purposes, as little use can be made of them as of the angles of the thorax. The pos- 

 terior legs are sometimes close to the intermediate ones, and sometimes far removed. 

 This character is constant throughout every genus, except Pterostichus, where there 



Bulletin Soc. Imp. Nat. de Moscou 1842, p. 24. 



