PLATE XIX. 



Page. 

 A VICULOPECTEN AFFINIS 229 



Fig. 1. Left valve of an average size specimen. 



la. Right valve of a smaller shell, in which the sinus is deeper beneath the anterior ear. 



A VICULOPECTEN EUREKENSIS '--' 



Fig. 2. View of a left valve compressed laterally. 



3. Left valve with the anterior ear restored in outline. Shell flattened by compression. 



AVICULOPECTEN HAGUEI 



Fig. 4. Left valve with the outline of the posterior basal margin restored from the matrix, 

 the margin of the shell having been broken away. 



MYALIXA NEMESIS -':'>? 



Fig. o. Left A r alve with the beak broken away. See plate xxii, tig. 7. 

 MYALIXA CONGENERIS 



Fig. 6. View of the smallest left valve collected. It is about three-fourths of rue size of 

 the largest specimen. See plate xxii, fig. 10. 



STREBLOPTERIA SIMILIS 230 



Fig. 7. Right valve. See plate viii, figs. 4, 4o-d. 



MODIOLA ? NEVADENSIS 239 



Fig. 8. View of a somewhat compressed specimen of the right valve. 



SANGUIXOLITES ? N^NIA 249 



Fig. it. Right valve. 



PTERIXEA PINTOENSIS 234 



Fig. 10. View of left valve, enlarged to two diameters. 



PINNA INEXPECTANS 235 



Fig. 11. View of posterior half of left valve. 





