1818.] OF THE UNITED STATES. 431 



&c.; when thrown on its back, turns with difficulty; ex- 

 ceedingly like the 0. asellusy which was some years since 

 in great repute in some parts of Europe for its supposed 

 virtues in the cure of pulmonary and other diseases, but 

 which is rejected as worthless by the present pharma- 

 logy; I consider ours as distinct on the authority of Mr. 

 Latreille's description of the European species; he ol> 

 serves that " les appendices interieurcs et intermediaires 

 de la queue depassent la piece superieure et terminale du 

 corps." 



Genm PORCELLIO. Latr. 



Caudal styles four, lateral ones biarticulate, interme- 

 diate ones concealed by the terminal segment of the tail; 

 antenn^y exteriores seven-jointed, interiores obsolete; tail 

 not abruptly narrower than the body. 



SPECIES. 



1. P. spinicornis** Body scabrous; antenncv, third 

 joint with a mucronate carina above. 



Inhabits North America, common. 



Cabinet of the Academy. 



JBody scabrous with granules, black-brown, margin 

 and submarginal lines cinereous, three dorsal lines ot al- 

 ternate yellowish subquadrate spots, of which the inter- 

 mediate ones are smallest; heady antenna^ and disk of the 

 tally blackish, the latter with two or three small yellowish 

 spots each side at base; antemice with the third joint ele- 

 vated above, and armed with an acute spine; terminal 

 joint of the tail canaliculate, hardly surpassing the first 

 joint of the exterior styles. 



Length two-fifths of an inch. 



