PLATE XXIII. 



PAGE 



Fig. 136. Tellina Mathewsonii. Natural size. 158 



Fig. 137. T. decuetata. Natural size. 158 



Fig. 138. ? T. quadrata. Natural size. 159 



Fig. 139. T. Ashburnerii. Natural size. 159 



Fig. 140. Venus (Mercenaria?) Varians. Natural size. 161 



140, a. Var. from near Martinez. 161 



141. Var. ? from Pence's ranch, Butte County. 161 

 Fig. 142. V. Veatchii. Magnified. 162 

 Fig. 143. Meretrix lens. Natural size. 164 

 Fig. 144. M. Hornii. Natural size. 164 

 Fig. 145. M. nitida. Natural size. 165 

 Fig. 146. M. nitida. Young. Natural size. 165 

 Fig. 147. M. longa. Natural size. 165 

 Fig. 148. Dosinia gyrata. Natural size. 168 

 Fig. 149. D. inflata. Natural size. 168 

 Fig. 150. Trapezium carinatum. Magnified. . 170 



Fig. 151. Cyprinella tenuis. Natural size. 170 



151, a. Hinge. 



Fig. 152. Cardium annulatum. Natural size. 171 



152, a. Magnified view of the surface. 



Fig. 153. C. Remondianum. Magnified. 172 



