Vol. IV] ANDERSON AND MARTIN— NEOCENE RECORD 55 



Type: — No. 237, Cal. Acad. Sci., in sea-cliff ^ mile west 

 of Twin Post Office, Clallam County, Washington. Coll., 

 Bruce Martin. 



Named in honor of Dr. C. F. Newcombe. 



Genus PECTEN Miiller 



Pecten sancti-ludovici, new species 



Plate 3, figures 10a and 10b 



Shell of moderate size, equivalve, inequilateral, strongly 

 ribbed, moderately inflated; umbones narrow and acute; each 

 valve with nineteen or twenty ribs, rounded on the back and 

 separated by narrow V-shaped interspaces; ribs ornamented 

 by about six riblets forming fasciculi more or less beaded or 

 roughened, not spiny; ears unequal, the anterior being nearly 

 twice the length of the posterior, and on the right valve coarsely 

 ribbed ; posterior ear smaller and ornamented with wavy radial 

 threads. 



Dimensions : — Altitude of the type specimen, 40 mm. ; width, 

 37 mm. ; thickness, both valves, 19 mm. 



This species differs from Pecten hastatus Sowerby, by hav- 

 ing uniform riblets. 



Type: — No. 107, and cotype No. 108, Cal. Acad. Sci., from 

 the Santa Margarita formation along the west side of the San 

 Juan River about one half mile above the mouth of Navajoa 

 Creek, northeastern San Luis Obispo County, California. Coll., 

 Bruce Martin. 



Pecten etchegoini Anderson 



Pecten etchegoini Anderson, Proc. Calif. Acad. Sciences, 

 vol, 2, p. 198, pi. 18, figures 92-93, 1905. 



Pecten (Chlamys) zvattsi var. niorani Arnold, U. S. G. S. 

 Professional Paper No. 47, pp. 121-122, pi. 10, figs. 3, 4, 5, 

 and 6, 1906. 



Pecten (Chlamys) zvattsi Arnold, var. etchegoini Anderson, 

 p. S. G. S. Bull. 396, p. 77, 1909. 



As the above named antedates the species and variety names 

 proposed by Arnold, by at least a year, by the rules of pre- 

 cedence it should stand, and if there are varietal forms that 

 merit distinct names these forms should be regarded as sub- 

 species of Pecten etchegoini Anderson. 



