206 • Kansas Academy of Science. 



34. Yoldia cooperi Gabb. Plate IV, fig. 34. 



Yoldia coopeH Gabb, Proc. Cal. Acad. Scf., vol.'III, 1865, p. 189; Pal. Gal., 

 vol. II, 1869, p. 31, pi. IX, fig. 54; Williamson, Proc. U. S. Nat. Mus., 

 vol. XV. 1892, p. 192; Dall, Trans. Wagner Inst. Sci., vol. Ill, 1898, p. 

 594; Arnold, Mem. Cal. Acad. Sci., vol. Ill, pp. 99, 100. In part, Cooper, 

 7th Ann. Rept. Cal. St. Min., 1888, p. 270; also, in part, Gabb (fide Pa'- 

 Cal.. vol. II, 1869, p. 59). 



Shell thin, oblong, very inequilateral, subcompressed; anterior 

 end subaccuminate, pointed, concave above; posterior end broadly 

 rounded; posterior ventral margin meeting the posterior extremity 

 in a broad, rounded curve, from which it continues broadly arcuate 

 to about opposite the beak, when it curves rapidly upward to the 

 anterior end; beaks minute and placed in advance of the middle; 

 surface sculptured by numerous small concentric ribs, which are 

 less abrupt on the upper side and slope downward on the side to- 

 wards the base; hinge with numerous sharp teeth; inside of shell 

 not seen. 



Dimensions of medium-sized mature specimen: Lat., 58; alt., 29; 

 umbo to anterior extremity, 17; to posterior extremity, 37. 



Dimensions of largest specimen figured: Lat., 58; greatest alt., 

 32; from umbo to posterior extremity, 40; to anterior extremity, 22. 



This species is quite variable, depending upon the age. It dif- 

 fers from Y. impressa Con. (Wilkes's Exped.) in its much greater 

 length and altitude and in its being more compressed. 



Living: Half Moon Bay, California (Arnold); San Diego to 

 Santa Sruz (Cooper). 



Pleistocene: Ventura, San Diego, Cal. (Arnold); San Pedro 

 (Arnold; Cooper), 



Pliocene: San Fernando (Cooper); Portata Valley. California 

 (Arnold). 



? Pliocene : Mouth of Quinaielt river, Granville, Wash. (Arnold ) ; 

 Quillayute, Wash. ( Reagan). 



Order Teleodesmacea; Superfamily Cardiacea. 



Family XXVI CARDiiDyE; Genus Cardium (Linne) Lamarck. 



Shell cordate, inflated, variously sculptured, usually striated or 

 radially ribbed, usually closed but sometimes slightly gaping; 

 beaks prominent; lunule or escutcheon absent; pallial line distant 

 from margin of the valves. 



35. Cardium meekianum Gabb. Plate IV, fig. 35; times, one -half. 

 Cardium meekianum Gabb, Pal. Cal., vol. II, p. 27, pi. 7, fig. 46, 1869. 



Gabb's description (in part) : " Shell large; beaks large, strongly 

 incurved and pointed forwards; shell broadly rounded anteriorly 

 and very oblique and abruptly truncated posteriorly; surface 



