Geological Papers. 105 



Cardium nuttallii (Mart.) Figures 8a and 86. 



Shell medium size, cordate, inflated, equivalve; each valve with 

 twenty-five to thirty angular imbricated ribs which seem to have 

 been continuous from beak to dorsal margin ( the surface of the 

 shells obtained are much worn); interspaces wider than the ribs; 

 surface marked with numerous transverse lines of growth; beaks 

 prominent; abductor scars subequal, pallial line entire. 



Dimensions: Length, 36 mm.; alt., 36 mm. 



Living: Puget sound; Georgian Bay. 



(?) Abra (?). Figure 9a. 



The teeth, pallial line and muscular impressions having been 

 removed from this shell, has made it impossible to identify it defi- 

 nitely. 



Macoma nasuta (Conrad). Figures 10a and 106. 



Arnold's description : ^ " Shell of medium size, ovate compressed, 

 thin ; anterior side dilated ; posterior side cuneiform, extremity 

 much above line of base ; posterior dorsal margin straight to angle 

 where it joins line of truncation ; fold carinated on right valve ; 

 umbone slightly anterior to center, slightly prominent, narrow car- 

 dinal teeth in each valve ; no laterals, ligament external, long, 

 straight, narrow ; pallial sinus large, expanding interiorly, that of 

 left valve joining anterior muscle impression at its lower posterior 

 angle. 



"Distinguishable from M. secta by smaller size, less convex 

 valves, less altitude, longer straight posterior margin, and larger, 

 less prominent ligamental callus; from M. inquinata by larger, 

 longer shell, less convex valves, less relative altitude, straight dor- 

 sal margin with truncation posteriorly, and by less central umbones ; 

 from M. yaldiformis by more cuneiform posterior extremity, long, 

 straight, posterior dorsal margin, and by having beaks anterior to 

 center rather than posterior; from i¥. «/?(ie7i^«i;a by beaks being 

 more anterior, being broader, and by lacking the prominent folds, 

 indentation of ventral margin, and prominent projection of poste- 

 rior extremity ; from M. kelseyi, which closely resembles it, by 

 broader shell and by more oblique truncation of posterior extrem- 

 ity. ..." 



Dimensions: Length, 30 mm.; alt., 22 mm. 



Living: Alaska to San Diego; Kamtschatka (Cooper). 



Pleistocene : Santa Barbara to San Diego (Cooper ) ; San Pedro ; 

 San Diego; Ventura (Arnold); Lummi; Blaine. 



8. Loc. cit., p. 163. 



