[ 139 J 



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

 America North of Mexico. By John L. Le Conte, M. D. 



(Concluded from page 112.) 



PART III. CONTAINIiNG THE LkUIM. 



The study of every group of highly organized animals is attended with great 

 difficulty. Whether our investigations relate to Hymenoptera, Lepidosteus, Croco- 

 dilus, the Corvida3, the Quadrumana, or (still more) the Bimana, almost insuperable 

 difficulties fill our path. These result from the very great uniformity of organization 

 which pervades such high groups. If the group be small in extent, then the 

 difficulty is in discovering specific characters ; if it be so numerous as to exhibit 

 considerable range of variation, then the genera, or groups of genera, become 

 indistinct in character, even though easily recognized by external characters. 



Such is the condition of the group now before us for consideration ; and although 

 my observations have been patient and as thorough as the material at my disposal 

 would permit, I am very far from being satisfied with the result of my labor. I 

 may, however, be permitted to remark that the primary division of this group by 

 Serville into depressed and convex genera, is too superficial, and leads to too much 

 confusion to need farther comment. 



On looking over a large series of Lamiffi, one becomes convinced that there are three 

 series of forms, and that in one or other of these every genus will at once find a place. 



The first and most numerous of these is the typical Lamia series, which attains its 

 highest development in Sternotoma, Ceroplesis, Omacantha and similar genera, 

 mostly from tropical Africa. To this series will be appended the Saperd^e, which 

 differ only by their unarmed, cylindrical thorax. In this series the head is always 

 as wide as the thorax, and the general form of the body, except when short and thick, 

 is cylindrical ; the humeri are always prominent. 



Connected in the closest manner with this series, and frequently anastomosing 

 with it, is a series which finds its highest development in Acrocinus, Macropus, 

 Oreodera, Megabasis, &c. ; they have the head narrower than the thorax, and the 

 body usually somewhat depressed, thus approaching to the ^diloid series mentioned 

 below. I was at first inclined to consider these as belonging to a separate series, but 

 after careful examination, I can discover no character on which to separate them. I 

 prefer considering them as a portion of the large Lamia series, parallel with the main 

 branch. 



