432 CRUSTACEA [November, 



A very common inmate of our houses, crawling up 

 the walls in damp cellars, S^c. It seems probable that it 

 resembles the P. scaber of Europe, of which however 

 we have no good description by which to judge. 



2. P. nigral. Black, scabrous, immaculate; antennae 

 witli the spine of the third joint hardly prominent. 



Inhabits Pennsylvania. 



Cabinet of the Academy. 



Body black, immaculate, beneath whitish, granular 

 numerous, elevated, very rough, segments of the tail 

 margined behind with abbreviated, elevated lines, termi- 

 nal segment acute, attaining the tip of the intermediate 

 styles and the middle of the last joint of the others. 



Length three-tenths of an inch. 



This species differs from the preceding, by being uni- 

 coloured, smaller and much more rough. 



Genus ARMADILLO. Latr. 



Caudal styles four, lateral ones biarticulate, contiivent 

 with, and not longer than the terminal segment of the tail, 

 second joint triangular; antenme^ exteriores seven-jointed, 

 interiores obsolete; body capable of being rolled into a 

 sphere. 



SPECIES. 



A. pilularis^. Plumbeous, margin and submarginal 

 line cinereous, three yellowish lines of spots on the disk. 



Inhabits North America. 



Cabinet of the Academy. 



Body with very minute punctures, lateral margin, and 

 submarginal line of spots, cinereous, three lines of large 



