228 



PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 88 



LEPAS PECTINATA PACIFICA, new subspecies 



Figures 2, 3 



HoMi/pe.—U.S.'NM. No. 78233, from Harriet Harbor, British 

 Columbia. 



Diagnosis. — Valves brittle and radially striate. No internal um- 

 bonal teeth. Ridge from umbo to apex of scutum close to occludent 

 margin. Occludent margin of tergum single, Tergum notched to 

 receive apex of scutiun. One short blunt filamentary appendage on 

 each side. No caudal appendages. 



Description. — The capitulum is rather thick basally. The plates are 

 white and the surface shows fine radial striations. The growth ridges 



FiGDRB 2. — Lepas pectinata paciflca, new subspecies, from Harriet Harbor, British Colum- 

 bia : a. Side view, X 2 ; 6, carina, external view, X 3 ; c, apex of capitulum from 

 above. X 3. 



are more or less prominent and uneven, particularly on the tergum. 

 The plates are very thin and brittle but the edges are not sinuous. 



The scuta are subtriangular, with the apex somewhat pointed. To- 

 ward the base they are concave internally. The occludent margin is 

 straight, and the ridge from the umbo to the apex is prominent and 

 never more than 1.5 mm. from the occludent margin. The basal mar- 

 gin is not straight but projects downward at the umbo. There is a 

 slight internal basal rim and in most a thickening externally on the 

 basal margin. There are no internal umbonal teeth. 



The tergum is triangular and has a notch, usually very conspicuous, 

 on the scutal margin very close to the occludent margin. The oc- 

 cludent margin of the tergum (fig. 2, c) differs from that of the typical 

 form in that it is restricted to a single side of the tergum instead of 



