V 



NATURAL SCIENCES OF PHILADELPHIA. 223 



largely increased. My views were not noticed in the excellent work of Duval,* 

 on the genera of the Coleoptera of Europe, in which, with the addition of some 

 genera not represented in our fauna, the classification remains as before. I 

 subsequently learned, by the reception of the very valuable work of C. G. 

 Thomson,! on the Coleoptera of Skandinavia, that several of the genera re- 

 cognized by me had been previously described by him, and, in fact, so far a3 

 his arrangement is applicable to our fauna, I have had occasion to make no 

 changes in the genera as limited by him. Within a few weeks I have received 

 a copy of the admirable work of Mulsant and Rey.J on the Terediles of France, 

 which would, indeed, have been exhaustive, if it had not happened unfortu- 

 nately, that the work of Thomson, above mentioned, remained unknown, to 

 the authors. The result is that all of the geuera described by Thomson have 

 received new names in this later memoir. 



It has been my endeavor, in the present brief treatise, to harmonise, with 

 the material before me, the views and names contained in the three works 

 quoted, and at the same time to arrange the genera in a more natural manner 

 than has been heretofore proposed. 



It has seemed to me that the genera form a nearly regular series, repre- 

 sented by species, more or less numerous, from those in which the members 

 (antennae and legs) are but slightly contractile, to those in which all are re- 

 ceived in appropriate excavations of the trunk ; from those in which the head 

 is scarcely deflexed, to those in which the mandibles in repose fit against the 

 mesosternum, shutting in the under surface of the head and prothorax. 



Considering the variation in form and structure of the antenna?, in genera 

 which are evidently closely related, I have regarded the manner in which the 

 body is contracted in repose as of fundamental importance in the classifica- 

 tion of the genera. 



I divide them, therefore, as follows : 



A. Head received in repose upon the under sur- 



face of the prothorax group Anobia. 



Prothorax not excavate beneath, head free., subgroup D r y o p h i 1 i. 

 Prothorax excavated beneath, for reception 



of head subgroup A n o b i a. 



B. Mandibles in repose, resting against the me- 



sosternum group Xtletini. 



Head excavated beneath for reception of an- 

 tennae subgroup Xy 1 eti n i. 



Antennas received between the coxa? subgroup Dorcatomata. 



In all the subgroups, excepting the first, (in which the contractile power i3 

 feebly developed,) there is great difference between the genera in the mecha- 

 nism adopted for the protection of the antennae, and a regular gradation in 

 the power of contractility, as will be readily observed by looking at the tables 

 of genera given below. 



Anobium pudicura Boheman, Eugenie's Resa, 86, is said to have been 

 collected in California, but as the localities of the insects of the expedition 

 3eem to have been confused, it may be regarded as a doubtful member of our 

 fauna. (Vide Eup actus.) 



I have excluded Ptili nus from this tribe ; it seems to me, as stated in 

 the Classification of Coleoptera of North America, to represent a separate 

 tribe, leading to the subfamily Bostrichidce. 



Subgroup I. DRYOPHILI. 

 In the species of this group the body is elongate, the head capable of being 



Genera dee Coleopterea d'Europe, par M.Juequelin Du Val, (Camille.) 



tScandinaviens Coleoptera synoptiskt bearbetade af C. G. Thomson. Lund, 1859 "863. 



X Hist. Naturelle des Uoleopteres de France, TereJiles par E. Mulsantget C). Key. Paris 1864. 



1865.] 



