22 THE NAUTILUS. 



Pholadidea, etc. Other crevices of this same blue clay yielded Ocin- 

 ebra and many of the finest Chitons obtained. 



Pholadidea penita Conrad. Found with the above. 



Pholadidea sagitta Stearns. Found with the above and at a depth 

 of 40 fathoms off Moss Landing. 



Pholadidea parva Tryon. In Haliotis shells. 



Pholadidea (Netastomella) darwinii Sowerby. 12 fathoms; in the 

 blue clay. 



Dentalium neohexagonum Pilsbry. 12 fathoms. 



Dentalium rectius Carpenter (?). 12 fathoms. One beautiful spe- 

 cimen over an inch long is probably referable to this species. 



Cadulus nltentior Carpenter. 12 fathoms; not uncommon. 



Tomatina harpa Dall. 12 to iO fathoms. 

 ( To be concluded. ) 



A NEW CEEITHIUM FBOM THE FLORIDA KEYS. 



BY WILLIAM HEALY DALL. 



Cerithium stantoni n. sp. 



Shell solid, acute, conic, the nine whorls rapidly enlarging ; sculp- 

 ture of 7-9 strong, rounded, axial ribs extending from the suture to 

 the periphery, crossed by small, sharply elevated, subequal, some 

 times alternate, close set spiral threads which cover the whole shell ; 

 these threads behind the periphery are white, the striae between them 

 tend to be blackish-brown except on the most prominent part of the 

 ribs where they are yellowish cream color ; from the periphery to 

 the canal the threads as well as the interspaces are brown, and on 

 the canal become lighter again, but are probably more or less var- 

 iable as in other species of the genus ; last whorl with a single varix 

 opposite the outer lip ; aperture semi-lunar, on the body callous, 

 with a strong subsutural ridge setting off a posterior sulcus ; the 

 pillar callous, twisted, very short, smooth ; the outer lip thickened, 

 reflected, internally sharply lirate ; interior white. Lon. of shell 35, 

 of last whorl 16, of aperture 12, max. diam. of shell 17, of aperture 

 6 mm. 



Shoals near St. George Cay, Belize, Rev. W. A. Stanton 

 (150294); Florida Keys (110469). 



