Page. 

 Fig. 12. Lkptosolen Conkadi 253 



12, a. A cast of the exterior of a right valve magnified as above (type-speuiuieu). 



12, b. A cast of the interior of the right valve (with the anterior end broken away), magni- 



fied to about one and a half diameters, and showing the furrow left, by the internal 

 ridge represented too pointed below. 

 I'lfi. 13. Piiotocardia Salinaensis - 174 



13, a. A cast of the exterior of a left valve, natural size (type-specimen i. 

 13, b. A profile internal cast, showing convexity. 



1:'., c. A view of internal east of left valve, natural size, showing muscular and pallial impres- 

 sions, costa", etc. 



13, <?. Same specimen as 13, a, magnified three diameters. 



Fig. 14. Cardium? Kansasense 170 



14, a. An imperfect cast of the exterior, showing remains of the small radiating costa\ 



14, b. An internal cast of a right valve, showing muscular and pallial impressions, and traces 

 of marginal crenulatious. 



14, c. The same view of a larger internal cast of a right valve, showing the casts of the cavi- 

 ties for the reception of the posterior aud anterior lateral teeth (pt and at) of the 

 other valve, as well as that for the reception of the principal cardinal tooth of the 

 other valve at ct (type-specimen). 



14, d. An anterior view of same, also showing a projecting point at. (p), apparently left by a 

 scar for the attachment of a pedal muscle, near the beak. 



2-2 



