Conehifera. 187 li-oeardia. 



crijptocems, d'Orb. (G.), P- F. 48, 252, 5, 7. 



longirostris, Roem. (G.), Nord. Kreid, 70, 9, 6. 



lunulata, Roem. not Nyst. (sublunulata), Nord. Kreid. 70, 9, 5. 



modiola, Nils. Sp. (G.), d'Orb. Prod. 242. 



JVeocomensis, Ag. Sp. (G.), d'Orb. P. F. 44, 250, 9-11. 



ohliqua, d'Orb. (G.), Prod. 163. 



Orhignyana, d'iirc. (IsOARCA obesa), M. G. S. F. 1847, pi. 



15, f. 1. 

 ornata, Forbes (Opts), Q. J. G. S. vol i, 242, 2, 10. 

 praehnga, Leym. (G.), M. G. S. F. 2d s. vol. v, 6, 8, 3. 

 pygmaea, Reuss (G.), Bohm. Kreid. 2, 35, 14. 

 Pyrenaica, d'Orb. (G.), P. F. 46, 251, 1, 2. 

 Renauxlana, d'Orb. (G.), Prod. 196. 

 semiradtata, d'Orb. (G.), Prod. 163. 

 simih's, Sow. (G.), M. Con. 616. 

 sublmndata, d'Orb. (G.), Prod. 242. 

 suhsinuata, Forbes (G.), G. T. vol. vii, 146, 17,*12. 

 frigona, Roem. (G.), Nord. Kreid. 70, 9, 7. 

 turgida, Reuss (cretacea), Bbhm. Kreid. pi. 40, f. 16. 



Washita, Marcou (G.), Geol. N. A. 37, 3, 2. 



Janira, d'Orb. not Schum. 1817* (NEITHEA, Drouet, 1821). 



aequkostafa, Lam. Sp. (N.), d'Orb. P. F. 637, 445, 1-4. 



alata, You. Buch. Sp. (N.), d'Orb. Prod. 107. 



Albensis, d'Orb. (N.), Prod. 139. 



Alphia, d'Orb. (N.), P. F. 643, 446, 4-8. 



Atava, Roem. Sp. (N.), d'Orb. P. F. 647, 442, 1, 3, 5. 



Carantonensis, d'Orb. (N.), Prod. 170. 



cometa, d'Orb. (N.), P. F. 642, 446, 1-3. 



craticula, Morton, Sp. (Pecten), d'Orb. Prod. 253. 



decemcostata, d'Orb. (N.), P. F. 669, 449, 1-4. 



Beshayesi'ana, Math. Sp. (N.), d'Orb. P. F. 626, 441. 



digitalis, Roem. Sp. (N.), d'Orb. P. F. 642, 446, 1-3. 



dilatata, d'Orb. (N.), P. F. 638, 445, 5-8. 



Dufrenoyi, d'Orb. (N.), Prod. 107. 



* The cretaceous species referred by d'Orbigny and others to the genus Janira. 

 are certainly genetically different from the type Pecten maximus. They form a 

 group to which Drouet gave the name Neithea. They have the following distin- 

 guishing characters, and appear to be peculiar to the cretaceous formation : the 

 lower valve convex, upper valve flat or more generally concave, and with about 

 six large ribs and several smaller intermediate ones. The large ribs give the 

 outline a somewhat angular form ; this last character is never seen in Janira, 



