ON A MAKINE SPECIES OF PHILOUGEIA. 



Plate XL 



By Charles Chilton, M.A. 



The Isopod described in this Paper was obtained at Coogee Bay- 

 near Sydney, on December 30th, 1883. I took it in considerable 

 numbers creeping on the under surface of stones, which were 

 completely covered by sea-water in rock-pools near high water 

 mark. 



The only Oniscince mentioned in Mr. Haswell's " Catalogue of 

 the Australian Crustacea " are Porcellio graniger and P. obtusifrons 

 so that my Isopod which belongs to the genus Philougria, is 

 evidently new to the Australian fauna, and as it differs from the 

 species of that genus which I can find descriptions of, I have 

 ventured to think it is new to science. On account of its 

 extraordinary habitat, I propose to call it Philougria marina. I 

 have not been able to find any record of other marine species of 

 the Oniscince, but it must be remembered, that the works of 

 reference at my disposal are very few in number. 



There can be little doubt that all the terrestrial Isopoda are 

 descended from marine forms, hence the question naturally arises 

 — is this Philougria a direct descendant of a form that has always 

 kept to its marine habitat ; or is it a terrestrial form that has 

 found it convenient to return to the original habitat in the sea ? 



