PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 



SMITHSONIAN INSTITUTION 



U. S. NATIONAL MUSEUM 



Vol. 106 Washington: 1956 Xo. 3376 



A NEW GENUS AND SPECIES OF MARINE .ASELLOTE 



ISOPOD. CAECIANIROPSIS PSAMMOPHILA. 



FROM CALIFORNIA 



Bv Robert J. Menzies^ and Jean Pettit' 



Specimens of marine asellote isopods representing a new genus and 

 new species were collected from a coarse-sand beach several centi- 

 meters below the surface of the sand, where they were associated 

 with living snails of the genus Caecum, the cmious pycnogonid 

 Rhyncothorax, and several kinds of polychaetes. especially some be- 

 longing to the Archiannehda. 



Besides the unusual ability of this species to live buried in sand in 

 the intertidal zone, it is of fm-ther interest in being the second known 

 American record of a bhnd intertidal asellote, the first being Caecijaera 

 horvathi Menzies (1951. pp. 1-7). a commensal with the wood-boring 

 isopod, Limnoria. 



The genus resembles Tkambema (Stebbing, 1913, p. 237), at least 

 superficially, in its elongated aspect and lack of eyes: for that reason 

 it perhaps belongs in the family Thambematidae (Stebbing, 1912, p. 

 42). Stebbing's report of a single pleotelsonal somite in Thamhema 



» Lament Geological Observatory of Colombia University, Palisades, X. Y. (This paper is Contribu- 

 tion Xo. 198 from the Geological Observatory and Contribution Xo. 1 of the Observatory's Biology Program.) 



441 



^6756—56 



