NATURAL SCIENCES OP PHILADELPHIA. 227 



and the posterior margin is obtusely angulated, as in Ozognathus. But five 

 ventral segments are visible. The tarsi are broad, shorter than the tibiae, 

 the first joint longer, the last joint dilated, furnished with a dense brush be- 

 neath ; the claws are distant and minute. 



The name A n o b i u m Fabr., should be retained for this genus, as it is 

 not only the first species described under the genus, (vide Fabr., Ent. Syst. 

 and Syst. El.,) but is the one which Olivier has assumed for the type, and 

 from which his drawings of the trophi were made. Nevertheless, with a 

 view of disturbing the synonymy less, other species have been assumed by 

 European authors as the types of the genus, and I have refrained from restoring 

 the generic name to the imported species, by which alone it is thus far 

 represented on this continent. 



1. X.tessellatum Motsch., Bull. Mosc, 1845, i. 35; Muls. and Rey , 

 Col. Fr. Terediles, 122. Anobium tessellatum Fabr., Eat. Syst., i. 236 ; Syst. 

 El., i. 321 ; Oliv Ent., ii. 16, tab. 1, fig. 1, &c. Cnecus tessellatus Thorns., 

 Skand., Col., v. 145. 



Introduced from Europe into the Atlantic States. Our largest species, and 

 varies considerably in size. 



Sub-Group II. ANOBIA. 



The body is usually elongate in form; the head capable of being strongly 

 deflexed, and resting in repose in the excavated under surface of the pro- 

 thorax ; the antennae are received between the anterior and middle coxae, in 

 a more or less distinct excavation, which is sometimes prolonged into the 

 metasternum. The mandibles do not reach the metasternum in repose, the 

 head is convex beneath, and not excavated for the reception of the antennae. 

 The antenna? have the last three joints generally larger, and the stem usually 

 not serrate, though these characters vary much. The anterior opening of 

 the prothorax is circular; the epipleurae are foveate in Petalium and 

 Th e c a; and the hind feet received in excavations of the first ventral seg- 

 ment in Theca and Eupactus. 



The genera are numerous. Those found in the United States may be 

 grouped as follows : 



f. First ventral segment not excavated for reception of 

 hind feet. 

 A. Metasternum not excavated in front ; 



a. AntennaB not received between the coxae, but 



resting upon them ; 

 Anterior coxae contiguous ; antennae 9- or 10-jointed Oligomerus. 

 Anterior coxae nearly contiguous; antennae 11- 



jointed S i t o d r e p a. 



b. Antennae received between the coxa?, which 



are distant ; 



Antennas subpectinated Ctenobium. 



Antennae not pectinated; 



Thighs strongly clavate, tarsi dilated Ptinodes. 



Thighs not clavate, tarsi dilated ; 



Claws armed with a broad tooth Tfichodesnia. 



Claws not toothed N i c o b i u m. 



Tarsi slender, thighs not clavate H a d r o b r e g m u s. 



B. Metasternum deeply excavated in front ; 



Antennae not serrate, last joints elongated Anobium. 



Antennae serrate, last joints scarcely longer Trypopitys. 



C. Metasternum produced in front into a large lobe ..Petalium. 

 II. First ventral segment excavated for reception of 



hind feet ; 

 Mesosternum carinate, epipleurae foveate at middle.. Theca. 

 Metasternum emarginate, epipleurae not foveate Eupactus. 



1865.] 



