110 Kansas Academy of Science. 



Macoma tampaensis (Conrad) (?). Figure 14. 



Shell ovate, rather inflated, thin ; urn bones subcentral to slightly 

 posterior to center ; anterior end slightly rounder than posterior; 

 no fold shown ; ligamental area short, scooped out. 



Dimensisions : Length, 13 mm. -^diameter, 8 mm.; umbones to 

 anterior extremity, 7.5 mm.; to posterior extremity, 6.5 mm. 



Living : Gordon's Pass, Fla. 



Macoma yaldiformis (?). Figure 15. 



Shell ovate to elongate ovate, compressed, thin ; anterior end 

 dilated ; posterior end slightly cuneiform, extremity somewhat trun- 

 cated ; posterior dorsal margin short, straight ; fold carinated on 

 right valve; umbones posterior; two (?) cardinal teeth in right 

 valve (left valve not seen); ligament external, short, straight; 

 pallial sinus large, wavy, expanding inside. 



Dimensions: Length, 18 mm.; diam., 12 mm.; umbones to pos- 

 terior end, 8 mm.; to anterior end, 11.5 mm. 



Saxicava rugosa (Linn.) Figure 16. 



Shell very variable in outline, generally angular oblong-ovate, 

 convex, thick; surface ornamented with conspicuous concentric 

 lines which give the surface a rugose appearance, these being more 

 prominent along the angles of the shell ; hinge area prominent ; 

 one prominent, well-forward tooth in the right valve (left valve 

 not seen ). 



Dimensions: Length, 11 mm.; alt., 6 mm.; umbones to anterior 

 extremity, 9 mm.; to posterior extremity, 3.5 mm. 



Living: Port Orchard, Wash. (Kincaid). 



Natica (Cryptonatica) clausa (Broderip and Sowerby). Figure 17. 



Arnold's description:^^ " Shell of medium size, ovate-globular; 

 spire only slightly elevated; whorls four, evenly convex, though 

 sometimes slightly shouldered; surface smooth, except for fine in- 

 cremental lines; suture impressed, distinct; aperture semilunar; 

 outer lip sharp ; inner lip callous and reflected completely over the 

 umbilicus. 



Living: Arctic ocean ; Alaska; north Atlantic (Cooper). 



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

 Santa Barbara (Arnold). 



Pliocene: San Pedro, Santa Barbara (Arnold). 



Dimensions : Alt., 27 mm.; lat., 26.5 mm.; aperture, 19.5x12 mm. 



11, Loc. cit.. p. 313. 



