PLIOCENE PECTENS. 119 



Pecten (Chlamys) Pakmklkei Dall. 



PI. XLI, titrs. 1. I'r, 5, and 'vi. 



1898. Peclen (Chlamys) I'nrmehvi Pali, Trans. Wagner Free Inst. Sci., vol. .3, pt. 4, p. 708, pi. 37, 

 figs. 14 and 14a, 1898. 



JJesi'/'/pfit'/i. — Shell iiveraying- aliout .">() millimeter.s in altitude, somewhat 

 shorter than high, rather compressed, ine([uivalve, equilateral; ears unecjual. 

 Left vahe with 5 prominent, narrow, smooth, and convex-topped ribs, separated 

 hy much wider interspaces which are sculptured by numei'ous, rather tine, radial 

 riljlets; whole surface of disk covered by profuse, coalescent, micro.scopically 

 checkered squamatioii; anterior ear produced and ornamented by several small 

 radials and microscopic sculptui'e; posterior ear short, but otherwise as anterior. 

 Right valve similar to the left, except that the ribs, which in the right valve corre- 

 spond to the interspaces of the left, are much broader than those of the left; 

 interspaces relatively narrower. The disks of both valves are constricted at irregular 

 intervals, which tends to give the ribs a nodose appearance. 



Dimeimtons. — Alt. -15 mm.; long. 38 mm. 



This species is close to P. xiolft'd Bernhardi. of Japan, but smaller, and differs 

 by the smooth top surface of the ribs, which in /'. mi^iftil are m(jre or less 

 striated or coarsely threaded, and by the not alternated radial riblets on the left 

 anterior ear; also, especially, by the peculiar microscopic squamation which makes 

 a complete external coating to the valve. P. jxiriiieleei. differs from P. roatUl by 

 its narrower ribs on the left valve, finer radials in the interspaces, less prominent 

 constrictions of the disk, and peculiar microscopic sculpture. 



Only two specimens of this species have "so far been found: a left valve (the 

 type, U. S. N. M. 154479) from the Pliocene at Pacific Beach, near San Diego, 

 and an imperfect right valve {\J . S. N. M. 164S42) from the Pliocene at Crescent 

 City, Cal. 



R.^NGE. 



Pliocene. Cre.scent City, Del Norte County, south side of Light-House Point, north 

 of wharf (Diller); Pacific Beach, San Diego (Parmelee). 



Pecten (Chlamys) washbuknei n. sp. 



PI. XLV, fig. 2. 



Description. — Shell averaging over lOU millimeters in altitude, somewhat 

 shorter than high, subequivalve, equilateral (except for the ears), rather tliin; 

 ba.se regularly rounded: sides somewhat concave above. Left valve with about 

 65 more or less unequal, faintly squamose, low, squarish ribs; interspaces about 

 as wide as the ribs, and sometimes ornamented by an intercalary thread or riblet; 

 whole surface of disk ornamented liy imbricating lamella'; anterior ear somewhat 

 convex in front, and with a faint suggestion of a notch, sculptured by about 12 

 rather low imbricated radials; posterior ear about one-half as long as the anterior, 

 obliquely truncated, and ornamented by faint radials and imbricating lamelhe. 



