PLATE II. 



Pag*. 



LINGULA ALBA-PINENSIS 108 



Fig. 1. Broad form, enlarged to six diameters. 

 Ic. Elongate form, enlarged to six diameters. 



LINGULA LIGEA 107 



Fig. 2. A typical specimen, enlarged to two diameters. 



LINGULA LIGEA, var., NEVADENSIS 107 



Fig. 3. Specimen showing the more attenuate form, as compared with fig. 2. Enlarged to 

 two diameters. 



LINGULA MELIE 274 



Fig. 4. A distorted specimen. Natural size. 



DlSCINA LODKNSIS 112 



Fig. 5. Ventral valve. Natural size. 



5 a. Dorsal valve. Natural size. 



PHOLIDOPS BELLULA 113 



Fig. 6. Ventral valve, enlarged to six diameters. 



6a. Cast of interior of ventral valve, enlarged to six diameters. 



6 b. Interior of ventral valve, enlarged to six diameters. 



PHOLIDOPS QUADRANGULARIS 114 



Fig. 7. Enlargement to three diameters of the type specimen. 



CHONETES DEFLECTA 124 



Figs. 8, 8 a, 86. Medium, transverse, and short forms of the ventral valve. Natural size. 



STROPHODONTA DEMISSA 118 



Figs. 9, 9a, 9 6. Lateral, ventral, and dorsal views of a specimen from Lone Mountain. 



PRODUCTUS IIIRSUTIFORME ." 133 



Fig. 10. Enlargement to three diameters of a small ventral valve, preserving three of the 



slender surface spines. 



10 a. A large ventral valve, showing a portion of the outer shell and cast of the inner 

 surface. 



STROPHODONTA INEQUIRADIATA 120 



Fig. 11. A strongly-marked fragment of the ventral valve. 

 11 a. Enlargement of the surface of fig. 11. 



ORTHIS TULLIENSIS 115 



Figs. 12, 12 a. Lateral and ventral view of an average size specimen. 



CHONETES MACKOSTRIATA 126 



Fig. 13. Dorsal view. Natural size. See plate xiii, figs. 14, 14a-c. 



