MUSEUM OF COMPARATIVE ZOOLOGY. 221 



Selenites Duranti, var. Catalinensis. 



Shell widely umbilicate, depressed, white, transparent when fresh ; whorls 

 4, flattened above and below, with fine oblique striae ; spire planulate ; aper- 

 ture transversely rounded ; peristome simple, acute ; extremities approached 

 and joined by a very thin callus in fully matured specimens. 



Greatest diameter, \ inch ; height, -^ inch. 



Habitat. Santa Catalina Island, California. 



My little shell differs from the typical Duranti in its greater size, smoother 

 surface, broader umbilicus in specimens of the same size, but principally in its 

 transparent shining surface. It is larger than the largest Duranti that I have 

 seen, but not so large as the costate variety of that species described by Mr. 

 Mazyck as distinct under the name of S. ccelata, which I have in my possession. 

 My specimen of that species is larger than his measurements. 



I can add the following to his locality : Los Angeles and San Diego, Cali- 

 fornia, Point Abunda, and banks of San Tomas River, Lower California; thus 

 giving it a range of about two hundred miles up and down the coast. I have 

 collected the typical S. Duranti at the following places : Etna Springs, Napa 

 Co., Healdsburg, Sonoma Co., Bolinas and San Rafael, Marin Co., Oakland, 

 Alameda Co., Santa Cruz, Monterey, Santa Barbara Island, Santa Catalina 

 Island, and San Clemente Island, a range of over one hundred miles north 

 and south. It is confined to the Coast Range as far as we know at present. 



