PTINIDAE. 225 



10. Antennse not serrate, joints 9-11 long. Anobium. 

 Aiitennse serrate, joints 9—11 scarcely longer. Trypopitys. 



11. Epipleura; foveate ; joints of antennae 9-11 long. Petalium. 



12. Mesosternum carinate ; epipleurse foveate at the middle; jdints of 



antennae 9-11 long. Theca. 



Mesosternum emarginate ; joints of antennae 9-11 large, thr last two 



closely connected, though not connate. Eupactus. 



Sitodrepa has been introduced in articles of commerce, and is 

 cosmopolitan; Ptinodes has one species in California. Hadro- 

 bregraus, Anobiuin, and Trypopitys occur on both sides of the 

 continent, as also Eupactus; the others are represented only in 

 the Atlantic region, Gastrallus in Colorado. 



Sub-Group 3. — X y l e t i n i . 

 Tills sub-group differs from the preceding only by the antennae 

 being curved around the under surface of the head in repose, 

 instead of being extended straight along the middle of the body; 

 the genera are but few, as follows : — 



First ventral segment not excavated. 2. 



First ventral segment excavated for tlie reception of the hind legs : joints 



of antennae 9-11 large. ,5. 



2. Elytra striate. 3. 

 Elytra not striate. 4. 



3. Antennae serrate, joints 9-11 elongate. Vrilletta. 

 Antennae serrate, joints 9—11 not longer. Xyletinus, 



4. Antennae serrate, joints 9-11 not longer. Lasioderma. 

 Antennae not serrate, joints 9-11 large. Catorama. 



5. Epipleurae not foveate. Hemiptychus. 

 Epipleurae foveate. Protheca. 



Except Protheca, which belongs to the Atlantic region, and 

 Vrilletta to the Pacific coast, these genera are represented on 

 both sides of the continent. 



Sub-Group 4. — D o r c A t o m a t a . 

 The body is oval-convex, or even globose, capable of lieiiig 

 closely contracted. The head, when deflexcd, is received into a 

 deep cavity of the prothorax, and the mandibles abut against the 

 front margin of the metasternnm, which is prolonged between the 

 middle coxic into a short broad lobe, nearly truncate i» iront. 

 The antennse are received in a deep sternal cavity between the 

 front coxae, and in the mesosternum, which is deeply buried under 

 the metasternal process: the 1st j(unt is large and auriridate, 

 15 



