NEW MOLLUSKS OF THE FAMILY VITRINELLJD^ FROM 

 THE WEST COAST OF AMERICA. 



B}" Paul Bartsch, 



Assistant Curator, Dlrisionof MoJlusks, V. S. Natioval Musewn. 



The United States National Museum has from time to time received 

 additions to the collections of this famil3% among which are quite a 

 number of undescribed forms. These are here diagnosed and figured. 



VITRINELLA OLDROYDI, new species. 



Shell small, sublenticular, semitransparent, a little more convex 

 above than below. Nepionic whorls not differentiated from the rest, 

 the entire upper surface smooth and shining, marked only by irregu- 

 larly distributed incremental lines. The upper sides of the whorls are 

 moderately and evenly rounded. Sutures well marked. Periphery of 

 the last whorl well rounded. Base moderately well rounded, openly 



Fig. 1.— VlTRINELL.i OLDKOYDI. a, TOP VIEW: 6, SIDE VIEW, C, BASAL VIEW. 



umbilicated to the very apex. Columellar wall of the base well 

 rounded (not concaved). Aperture decidedly oblique, broadly oval; 

 outer lip thin; columella decidedly curved and somewhat expanded at 

 its insertion; parietal wall covered b}^ a rather strong callus which 

 partly fills the posterior angle. 



The type, Cat. No. 158777, U.S.N.M., was collected in low water at 

 Point Loma, California. It has three and three-fourths whorls and 

 measures: Greater diameter, 2.1 mm.; lesser diameter, 1.6 mm.; alti- 

 tude, 0.8 mm. 



Proceedings U. S. National Museum. Vol XXXII— No. 1520. 



167 



