PTINIDAE. 205 



The type of Coelostetlius is Anobium notatum Say; A. quad- 

 rulum Lee. also belongs to it ; of Ptinodes, Anobium setiferum 

 Lee. ; of Trichodesnia, Anobium gibbosum Say. To Hernicoelus 

 belong A. gibbicolle Lee, and carinatum Say. 



The type of Nicobium is A. sericeum Mels., and of Cacotemnus 

 is A. errans Mels. To Oligomerus belongs A. thoracicum Mels. 

 The type of Petaliuni is Anobium bistriatum Say, a very small 

 elongated species; the antenna? are 10-jointed, the 4th joint is 

 triangular, and the 5 — 7 small and closely connected ; the three 

 outer ones are larger. The mesosternum forms a large transverse 

 plate, rounded in front, covering the anterior coxae and almost 

 meeting the head in repose, and the middle tarsi are received in 

 a deep groove each side between it and the metasternum ; the 

 second ventral segment is very long ; the elytra have but two 

 striae near the margin. 



Group III. — Dryophili. 



The mandibles are not dilated at the base ; the head is wider 

 than in the preceding group, and the eyes are sometimes very 

 large and prominent. The antennae are 11-jointed, and the outer 

 three joints are longer, and sometimes (Dryophilus) attain a very 

 great length. The prothorax beneath is not hollowed out for 

 the protection of the under surface of the head, which is not 

 applied so closely to the breast in repose as in the preceding 

 group. The prosternum is sometimes more developed in front of 

 the coxae, than in the Anobia ; there is never any pectoral excava- 

 tion. The elytra are not punctured in rows ; the plates of the hind 

 coxae are very small and almost vanish externally ; the last joint 

 of the tarsi is short and dilated in Xestobium, but is longer and 

 narrow in the others. 



Our genera are four, and may be thus distinguished : — 



Prosternum very short in front of the coxae ; 



Anterior coxae separated by the prosternum. Xestobicm. 



Anterior coxae contiguous. Philoxylox. 

 Prosternum well developed in front of the coxae ; 



Anterior coxae contiguous. Dryophilus. 



Anterior coxae separated by the prosternum. Ozognathus. 



Of Xestobium we have only the European X. tesselatum, which 

 has been introduced. Dryophilus and Philoxylon occur on both 

 sides of the continent. Ozoguathus is founded upon the Califor- 



