258 [January, 



related to C elegant, of Deshayes; two remarkable species which have no 

 analogue or kindred shell in later Tertiary formations. The state of preserva- 

 tion and the forms of these fossils are closely analogous to those of the Paris 

 basin"; and I find no recent nor any Miocene species among them. I believe the 

 group to be newer than the Claiborne deposit, and certainly older than that of 

 Vicksburg. 



I think it will be found that No. 6, of the above table, represents that exten- 

 sive limestone, which, in Alabama, contains the Basilosaurus remains ; the 

 Laganum Rogersi, Morton, near Claiborne, and near Brandon, Mississippi, where 

 it has been discovered by Col. Wailes, occupying a higher position than the Jack- 

 son group. The limestone of Jacksonboro', Georgia, described by Lyell, is pro- 

 bably referable to the same division, and contains the Laganum Rogersi, (Scu- 

 tella Jonesi, Forbes.) 







The following species of organic remains were collected by Col. B. L. C. 

 Wailes, and are figured in his work on the Geology of Mississippi. Those 

 illustrations are referred to in the descriptions. 



CORBULA. 



1. C. densata, Geol. of Miss. PI. xiv., fig. 9 Triangular, subequilateral, very 

 thick in substance ; surface undulated and having angular concentric striae; um- 

 bonal slope submarginal and acutely carinated, posterior extremity angular. 



Related to C. nasuta, Con. but proportionally shorter, thicker, with a more 

 rounded base, &c. The description applies to the larger valve, as I have not 

 seen the opposite one. 



2. C. licarinata, PI. xiv., fig. 3. Elevated, triangular, slightly oblique, thick 

 in substance, profoundly ventricose, with robust reflected concentric lines ; umbo 

 profoundly prominent, and the beak incurved; posterior slope biangulated ; space 

 between the angles flattened, direct. 



Resembles C. o?iiscus, Con., but is thicker, more elevated, not rostrated, and 

 its slight obliquity is the reverse of that in the former species. I have not seen 

 the smaller valve. 



LED A, Schum. 



L. multilineata, PI. xiv., fig. 4. Ovato-elliptical, inequilateral, ventricose, 

 with fine sharp concentric lines, which are somewhat undulated ; anterior side 

 rostrated, with closely-arranged, radiating, minute, tuberculated striae; posterior 

 side with unequal fine radiating lines, a few of which are very distinct; a few 

 radiating lines are continued near the base ever the middle of the valves. 



Allied to N. ccelata, Con., but very distinct. 



NAV1CULA, Blainville. 



N. atpera, PI. xiv., fig. 5. Trapezoidal, disk contracted behind the middle, 

 cancellated; concentric lines distant, imbricated ; radiating lines largest towards 

 the umbonal slope, subspinous ; umbonal slope acutely angulated ; posterior slope 

 excavated ; series of cardinal teeth uninterrupted ; inner margin crenulated. 



CARDIUM, Lin. 



C. (Protocardia) Nieolletti, PI. xiv., fig. 6. Proceed. Acad. Nat. Sc, 1841, p. 33. 



This shell agrees, except in size, with the specimen originally described from 

 the Washita, and doubtless the beds of that locality will prove to be of synchron- 

 ous origin with those of Jackson. A species of Cardium very nearly allied to 

 this, 1 formerly believed to be the same; but it accompanies a different group, 

 and presents variations entitling it to be a specific distinction. 



It is from Pamunkey river, Virg. 



Compared with C. Nieolletti ; umbo less inflated, posterior margin oblique, shell 

 proportionally longer, and the radiating lines 22; in the other 25. The posterior 

 cardinal tooth larger, &c. It may be named C. lene. 



