124 bulletin: museum of comparative zoology. 



Eemarks. The species is established essentially on the very large male, the 

 mouth parts of vhich are very different from those of other forms known to 

 me. I hope that it wiU prove to be rather easy to recognize the form, but I 

 hesitated to establish the new genus, the knowledge of the female being very 

 incomplete. However, I found it impossible to refer the species to any of the 

 genera hitherto published. 



ONISCID^. 

 15. Porcellio laevis Latr. (1804). 



I will only refer to the account in G. Budde-Lund's Crustacea Isopoda Ter- 

 restria, 1885, which is the principal work on the Oniscidse ; the author (pp. 138- 

 140) describes the species, presents an enormous quantity of synonymy and 

 references to earlier authors, and adds a very long list of localities for this 

 almost cosmopolitan form. 



Habitat. Chatham Island, Galapagos (March 29, 1891), four specimens (de- 

 termined by G. Budde-Lund). 



Zoological Mcsecm, Copexhagen, 

 September 16, 1897. 



