Vol. VII] WARING— STRATIGRAPHIC AND FAUNAL RELATIONS 75 



ing steeply ; anterior margin rounded ; posterior cardinal mar- 

 gin sloping gradually ; posterior margin truncated ; basal mar- 

 gin slightly convex ; umbonal ridge faint ; exterior marked by 

 fine lines of growth, with obscured radial ribs; hinge with two 

 large teeth anteriorly. Locality 4, L. S. J. U. Pal. Coll. 



Cucullaea mathewsonii Gabb 



PI. 12, Figs. 14, 18 and 19 



C. mathewsonii Gabb, Pal. Gal., vol. 1, p. 195, pi. 31, fig. 266. 



C. matheivsonii Gabb, 17 An. Rept. U. S. G. S., pt. 1, p. 

 1039, pi. 64, figs. 4 and 5. 



Shell large, thick, gibbous, subquadrate, rounded in front and 

 on the base ; truncated posteriorly ; beaks large, subcentral and 

 incurved ; area long and wide ; hinge line nearly as long as 

 greatest length of shell ; surface marked by many small rounded 

 ribs, sometimes grooved longitudinally ; ribs very fine, posterior 

 of umbonal angle; fine lines of growth cross radial ribs; basal 

 margin of large specimens figured are truncated and marked 

 by coarse lines of growth, probably due to age. Locality 5, L. 

 S. J. U. Pal. Coll. 



Glycimeris veatchi major Stanton 

 PI. 10, Figs. 3 and 4 



G. veatchi var. major Stanton, 17 An. Rept. U. S. G. S., pt. 

 l,p. 1040, pi. 64, figs. 2 and 3. 



The specimens of this subspecies are much smaller than 

 those of the Chico species, Glycimeris veatchii Gabb, of the 

 southern area. The shells of the specimens are thinner than in 

 the Chico species and are nearly equivalve. Cardinal margins 

 sloping steeply; posterior slope somewhat truncated; very faint 

 depressions in posterior sides of umbones pass down and strike 

 middle of posterior margin. In the Chico form these depres- 

 sions are very marked. Hinge robust and teeth arranged radi- 

 ately ; area short and narrow ; surface ornamented with rounded 

 radial ribs wider than interspaces. Locality 4, L. S. J. U. Pal. 

 Coll. 



