Notes on Pondicherry Fossils. 24o 



near the mouth of a river ; or, as frequently proved to have been the 

 case in Europe, in a basin, alternately subject to salt and fresh water. 



Melania ? — This is another fresh-water genus ; but it is to be re- 

 gretted, that the only specimen in the collection is imperfect. The spire 

 is short, consisting of four whorls, longitudinally ribbed ; there is, how- 

 ever, some uncertainty, the upper portion of the aperture being partially 

 removed, as well as generally injured. 



Scalaria. — Of this genus there are numerous species, many with trans- 

 verse ridges on the spire ; in some the whorls are rounded, in others 

 flattened. The following species may be distinguished : — 



1. Scalaria annulata, J. M. — Shell elongated and conical, whorls 

 convex, with three or four narrow transverse grooves and obscure 

 ribs on each; upper part of the aperture slightly raised or expanded. 

 This species is larger than any of the others. There is not a perfect 

 specimen in the collection ; but several fragments, consisting of the 

 aperture and the last whorl. The largest of these is three-fourths of an 

 inch in diameter. 



2. Scalaria zonata, J. M. — Shell elongated and conical, whorls con- 

 vex, with four ribs on the two last. The ribs on this species are more 

 strongly marked and prominent, and the whorls less convex than in the 

 last. The specimens are all incomplete. 



5. Scala?ia Kayeii, J. M. — Shell conical, spire consisting of four 

 convex smooth whorls. There is but one specimen of this species in the 

 collection, which is named in complement of one of the discoverers of 

 these interesting remains. 



3. Scalaria tricostata, J.M. — Shell conical, sides of the spire straight, 

 the whorls being merely separated by a groove, and distinguished by 

 three costse, or spiral ridges. 



4. Scalaria bicostata, J. M. — Shell conical, sides of the spire straight ; 

 the whorls separated by a deep groove from each other, and a small 

 spiral groove on each, dividing them into two costse. 



Nerita transversaria, J. M. — Spine transversely striated by lines of 

 growth, internal margin of the aperture toothed. This genus is both 

 fresh water and marine. The marine species (of which this fossil is one) 

 are known by the denticulated margin. There is but a single specimen 

 in the collection, of which the outer portion of the margin is broken 

 and imperfect. 



Natica sulculosa, J. M. — Shell subglobose, spire equal to the height of 

 the aperture, umbilicus consisting of a small transverse fissure. There 

 is but one specimen of this shell in the collection, and that rather 

 imperfect. 



