362 MEMOIRS ON THE COLEOPTERA 



Form less convex, extremely dull or opaque, black; elytra (9) entirely 

 without lustre, flat; prothorax wider than long, rounded and rather 

 strongly margined on the sides, which are very shortly sinuate be- 

 hind; hind angles rectangular; base not narrower than the apex, the 

 anterior impression [perhaps the incised subapical line is intended] 

 deep, hind one well marked; foveae deep, bistriate, with a short ex- 

 ternal carina; elytra oval, scarcely wider than the prothorax; humeri 

 broadly rounded; tip scarcely sinuate; striae fine, punctured; mar- 

 ginals not approximate; interspaces broad and flat, third with the 

 usual puncture; prosternum very deeply sulcate. Length 18 mm. 

 Louisiana (Red River) nonnitens Lee. 



The species named enormis above I had labeled nonnitens in my 

 collection for many years, but a recent inspection of the original 

 description of nonnitens, of which a virtual transcription is given 

 in the table, shows that this identity is improbable. The elytra 

 are notably wider than the prothorax in enormis and by no means 

 flat, the marginal stria close to the eighth and the subapical sinus 

 is distinct. The posterior transverse thoracic impression is obso- 

 lete, except in a depression at each side near the inner fovea, as 

 pronounced a feature here as it is in seximpressus, where it served 

 to suggest the name given by the describer; it is distinct also in 

 almost all the other species. As the unique original type of non- 

 nitens was also a female, these comparisons seem to indicate that 

 enormis is a different though allied species. 



I am unable to identify the species described by Chaudoir (Rev. 

 Mag. Zool., 1868, p. 52) under the name Evarthrus acuminatus, 

 and no reference to it appears in the work of LeConte. It is com- 

 pared with seximpressus, but the basal parts of the prothorax ac- 

 cord better with the genus Megasteropus where, however, the acu- 

 minate elytra described in acuminatus, are not apparent. Only an 

 inspection of the type can decide where it belongs. 



It is possible that the incised line along the apical thoracic mar- 

 gin, well developed in all the species, though finer in parallelus, may 

 have been alluded to sometimes as the anterior thoracic impres- 

 sion. The true anterior transverse impression is always feeble and 

 more diffuse, lying well behind this incised line when it is present 

 at all;. it is usually completely obsolete in Evarthrus, though fre- 

 quently distinct in Anaferonia. 



