490 ONISCID^. 



from P. pruinosus, in company with which it is often 

 found, and of whicli it might be mistaken for the young, 

 which latter, however, do not differ from their parents. 

 The basal portion of each of the segments of the body 

 is marked with a transverse raised line, whence the name 

 given by Professor Kinahan to the species. It is of a 

 dark steel colour, with red and yellow spots. It runs 

 with very great rapidity, and never rolls itself into a 

 ball, as might indeed be surmised from the small develop- 

 ment of the lobes of the head, which form, in other 

 species, the defence of the antennas when at rest. 



It is very rare. Specimens taken near Dublin by 

 Professor Kinahan, are in the collection of the British 

 Museum and our own cabinet. 



