386 ZOOLOGY. 



Family A N A T I N 1 D JI • 

 MYTILIMERIA NUTTALLI. 



Mytilimeria nuttalli, Conr. Journ. Acad Phila. VII, p. 247, pi. 19, f. 5. — Carp. Eep. p. 301. 

 Uab. — San Diego ; Lieutenant W. P. Trowbridge. 



A small group of this curious shell, nestling in a white friable arenaceous substance, was 

 received by the Smithsonian Institution through the kindness of Lieutenant Trowbridge. 



Family PHOLADIDAE. 



PHOLAS PENITA. 



Pliolas penita, CosR. Jour. Acad. Phila. VII, p. 237, pi. 18, f. 7, 1837. 

 Plwlus concamerala, Deshayes, Eev. Zool. p. 234, 1839. — Idem, Mag. de Zool. pi. 17, 1840. 

 Paropholax jienita, Conr. Jour. Acad. Phila. 1849, p. 214. — Carp. Rep. p. 290. 

 H'lb. — Shoalwater buy, Dr. Cooper; Straits of Fuca, Dr. Suckley; Oregon, mouth of Umpqua river. Dr. VoIIum, U. S. A. 



"A specimen was obtained from a piece of worn rock which drifted into the bay attached to 

 the roots of macrocystis, the giant sea- weed." — C. 



