AMERICAN COLEOPTERA. 69 



Notes on the species or ASAPHES of Boreal America. 



BY GEORGE H. HORN, M. D. 



xY study of this genus based on the accumulation of material since 

 Leconte's Revision has led me to conclusions hardly expectpd at first. 

 Starting with the idea that the species should be separated by some 

 characters capable of definition and which could be used as a key, 

 it became evident at once that this was not easily to be done. At a 

 glance in our cabinets it will be seen that certain species are normally 

 black while others are brown, ferruginous or even paler, and while 

 this would make a tolerably good empirical division it is certainly 

 not natural. The absence of the carina at the hind angles of certain 

 forms and with it the absence of the intra-angular incisure is the first 

 character of importance to be observed. In those species in which 

 the color above and beneath is entirely black, the flanks of the pro- 

 thorax beneath are usually densely but always equally punctured, 

 while in the paler species this part of the body is very unequally 

 punctured, it is usually densely punctured in front and with a large 

 smooth space posteriorly, in one or two species there is no space free 

 of punctures but the punctures are so very sparsely placed as to make 

 a very considerable contrast between the anterior and posterior por- 

 tion of the flanks. This character separates very nearly those species 

 (with a carina), which are totally black from those which are not so. 

 The form of the prosternal mucro has also a certain value in sepa- 

 «ting the species. In some it will be noticed that the median line 

 of the prosternum to the tip of the mucro is straight and the bifid 

 mesosternum is also nearly in the same ph*ne with the metasternum 

 the lobes being rather prominent. In o'jhers the mucro is flexed 

 behind the coxae and the mesosternum quite oblique its lobes not 

 prominent. By the use of these characters we avoid the necessity 

 of separating species by the thoracic punctuation, a rather variable 

 and unsafe character. 



Dr. Candeze has separated as distinct species some forms in which 

 the inner striae of the elytra are more or less efiaced, but it will be 

 observed that this is a sexual character, and is often seen in the 

 females though not constant in that sex but I have never noticed it 

 in the males. 



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