OF CONCHOLOOY. 173 



culated, its external margin crenulated ; coluuiella excavated ; 

 aperture ovate, light purple to purplish brown ; canal short, 

 moderately curved, in some specimens closed, in others, of equal 

 or larger size, open; umbilicus nearly obsolete; surface tra- 

 versed by about fourteen roughly rounded revolving costse, 

 more or less varicose or tuberculated at the intersection of the 

 longitudinal ribs and varical ridges ; also marked with fine in- 

 cremental strise, the latter being more conspicuous in the inter- 

 costal sulcations ; color white, somewhat dingy, with two inter- 

 rupted zones of black or dark brown on the !)ody whorl. 



Number of specimens examined sixteen, mostly immature ; 

 the dimensions of the largest are respectively : 



Length, *85 ' '80 *75 inch. 



Breadth, -50 -47 -45 inch. 



Habitat, Monterey, California, where it has been collected by 

 Messrs. Hemphill, Harford, Gordon and myself. 



This shell is Oemebra var. o of Carpenter (MSS.), and 702 

 (in part) of Cooper's Geog. Cat. Moll. 



The above species varies considerably in robustness, length of 

 spire and development of sculpture ; it is exceedingly charac- 

 teristic in its markings, and easily distinguished from all others 

 belonging to the Californian group of the Ocinebrce ; it is not 

 numerous in individuals, and appears to be exceedingly limited 

 in its distribution. 



Since writing the above, additional specimens have been for- 

 warded to me by Mr. Harford, collected by him at the Island of 

 San Miguel, off Santa Barbara, Cal. These latter specimens show 

 a much more prominent longitudinal sculpture than the Monterey 

 specimens, are generally more rugose, and one specimen is ashen 

 white and wants the interrupted color bands. 



