328 Coleopterological Notices. 



of the prothorax, and more angulate frontal umbo; in Isevis the 

 elytral series become obsolete slightly behind the middle and are 

 composed of much finer punctures than in lecontei. In the very 

 large series of Isevis from various localities which I have before me, 

 there are indications of several more or less distinct varieties. 



Epitragini. 



There seems to be a certain bond of affinity uniting the genera 

 Euvymetopon, Emmenastus, Auchmobius, Cnemodus, Epitragus, 

 Schcenicus, Chilometopon and Trimytis, which is expressed not 

 only by a general similarity of habitus, but also by important 

 structural peculiarities. The abdominal process for example is 

 acute or acutely rounded in all, the posterior coxse, in a transverse 

 sense, are long, subparallel and linear, being also generally more or 

 less oblique, and the metasternum has a broadly interrupted trans- 

 verse groove, 1 parallel and very near to the posterior margin ; this 

 groove becomes subobsolete only in a few aberrant species of 

 Emmenastus and in Trimytis, — both of which must be considered 

 as degradational types, — where it is represented by a series of finer 

 punctures which is generally more or less broadly impressed. The 

 wings are very exceptionally absent and are usually well developed. 

 In the opinion of the writer these genera should constitute, there- 

 fore, but a single tribe as named above, which may readily be sub- 

 divided into groups. The Epitragini are peculiarly American. 



The Gnathosiini, comprising the genera Gnathosia, Stibia, Tri- 

 orophus, Triphalus, Pachychila, Anatolica, Tent} T ria, Microdera, 



1 This groove, although possibly corresponding to the transverse metasternal 

 line of the Carabidfe, is not at all similar to it. In the case of the Carabidse, 

 the line is perfectly continuous, and completely separates from the main body 

 of the metasternum a transversely triangular " ante-coxal piece ;" here, how- 

 ever, there are really two independent grooves, which generally — though not 

 always — begin at the posterior margin near the inner side of the acetabulum, 

 and extend outward, parallel in curvature with its anterior edge, abrnptly 

 terminating before attaining the episternum. The exact taxonomic value of 

 these grooves I have not ventured to determine, but they constitute a very 

 constant character throughout the greater part of the Tenebrioninpe, and the 

 Epitragini, in which they are also well developed, seem to approach that sub- 

 family in abdominal structure more closely than any other tribe not included 

 within its limits, for in some specimens, especially of Chilometopon, there 

 appears to be a rudimentary coriaceous margin at the middle of the third and 

 fourth ventral segments. 



