522 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 51. 



Kiver, 4 miles below Bainbridge, Decatur County, Georgia; T. W. 

 Vaughan coll. 1900. U. S. Nat. Mus. Cat. No. 166743. 



This fossil, of which no perfect specimen was collected, has such 

 characteristic sculpture that even a fragment of it can be identified. 

 Some little doubt as to its genus existed, as some species of Van%koro 

 have an analogous sculpture. These, however, have a different aper- 

 ture, and there can be little doubt that the present species should 

 group with the imperforate Ijiotias, 



NERITA TAMPAENSIS Dall. 



Nerita tampaensis Dall, Trans. Wagner Inst. Sci. Phila., vol. 3, pt. 2, 1892, p. 421, 

 pi. 17, fig. 3; Bull. U. S. Nat. Mus. No. 90, 1915, p. 114, pi. 16, fig. 2. 



Locality. — Station 7075, on the east bank of Flint River, about 

 10| miles below Bainbridge, Decatur County, Georgia, and just 

 above Lambert Island; Cooke and Mansfield, 1914. U. S. Nat. 

 Mus. Cat. No. 166799. Also in the Orihaulax pugnax zone at Ballast 

 Point, Tampa Bay, Florida, and various other localities about Tampa 

 Bay; Dall and Burns. 



DENTALIUM LADINUM, new species. 



Plate 85, fig. 6. 



Shell slender, slightly curved, strongly sculptured, the posterior 

 end more or less incrusted by matrix and the anterior end defective, 

 but the section in front seems to be practically circular; near the 

 posterior end there are 10 or 11 longitudinal ribs, subequal and sepa- 

 rated by wider interspaces ; at about one- third the distance from the 

 posterior end finer intercalary threads begin to appear, sometimes 

 two, usually one, and rarely none in the widening interspaces. These 

 gradually enlarge until anteriorly they become equal to the original 

 ribs, and all the ribs toward the aperture are more or less paired. The 

 surface in the specimen is largely granulose, but this is probably an 

 incident of silicification; a few indications of incremental lines are 

 perceptible near the anterior end. Length of the specimen, 36; 

 diameter anteriorly, 5 ; posteriorly, 2 mm. 



Locality. — Station 6774, at Rock Island, in the Suwannee River, 

 about half a mile above the wagon bridge at White Springs, Hamil- 

 ton County, Florida; Vaughan and Cooke, 1913. U. S. Nat. Mus. 

 Cat. No. 166746. 



