386 ZOOLOGY. 



Family A N A T I N 1 1) M - 

 MYTILIMERIA NUTTALLI. 



Mytilimeria nuMalli, CONR. Journ. Acad Phila. Vil, p. 247, pi. 19, f. 5. CARP. Rep. p. 301. 

 Hob. 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. 



Phda* penita, CONR. Jour. Acad. Phila. VII, p. 237, pi. 18, f. 7, 1837. 

 Pholus concamerata, DESHAYES, Eev. Zool. p. 234, 1839. IDEM, Mag. de Zool. pi. 17, 1840. 

 Parapholas penita, CONR. Jour. Acad. Phila. 1849, p. 214. CARP. Rep. p. 290. 

 Sab. Shoalwater bay, Dr. Cooper ; Straits of Fuca, Dr. Suckley ; Oregon, mouth of Umpqua river, Dr. Vollum, U. S. A. 



&quot;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.&quot; C. 



