366 mS M. Safford on the Cretaceous 
16. Ostrea Larva, Lam., (Syn. O. falcata, Mort., not Sow.) - -a, 5,64, 
17. O. plumosa, Mort., - - - - - a, b, 
18. O. lecticosta, Gabb, —- - - - - a,bed, 
(I think this must be O. crenulata, Tuomey.) 
19, Hrogyra costata, Say, - - ‘ ‘ - 65,64 
20, Gryphea vesicularia, Lam., - - - . a, b, ¢. 
(Syn. O. convera, Say, and G. mutabilis, Mort.) 
for - - - - 
21. G. Vomer, Mort. - a, , 
22. Anomia tellinoides, Mort., - - - - a, b, 
23. A. Argentaria, Mort.,  - ee = -. Ohne 
24. Placunanomia Saffordi,Con., - ‘- - - a,b,o,d. 
(Syn, P. lineata, Con. P. lineata can be connected with P. Sa 
fordi by intermediate forms. The species is an abundant and 
variable one. Its individuals are often much larger than those _ 
fi . 
ed. Figure 21, pl. 46, (Jour. Acad., vol. iv.) sh ws the ap- 
_ pearance of the tooth after the enamel, that coats the inside of the 
valves, has been removed. Since the species was described, a few 
25. Scalaria Sillimani, Mort., “ 
26. Natica rectilabrum, Con., fe . 
27. Volutilithes Texana, Con., ae * 
28. Rapa (Pyrula) Richardsonii? Tuomey, - 
FREER 
29. R. trochiformis, Tuomey, 
30. Anchura abrupta, Con., 
g 
) Saf ee 
= 
1. Baculites yi » pay, 
32. Enchodus ferox, Leidy, “ : 
83. Sphyrena, sp. ? - 
34, Ischyrhiza mira, - e 
Besides these, I have in my collection from this bed uncertal 
species of Teredo, Serpula, Rostellaria, Fusus, Turritella and Del- 
phinula. : 1 
8. Ripley Group.—This is a provisional series, and 1s ey” 
upon observations made along and in the vicinity of on 
Memphis and Charleston Railroad. It is only in this region t 
determinable species have been found, although search has De*" 
made elsewhere for them. Its northern extension has beet ™ 
ferred from the general bearings and relations of its strata 
of those of the adjacent groups. ) 
Its outcrop occupies a belt of the surface, (8,8, on the pe 
extending through the State and being, along the railroad, & mh 
fifteen miles wide, but having a less average width. This che 
is in general rough and hilly. The high ridges dividing © 
— of the Tennessee and Mississippi rivers lie mostly WI" 
) 
SSS s 
- 
