6 TKITON. 



RANELLA, Lamarck. Shell ovate or oblong, compressed, with two rows 

 <»f continuous varices, one on each side ; aperture oval ; columella 

 arcuated and ridged, or crenulated ; canal short, recurved ; outer lip 

 crenated. 



There are over fifty recent species. In the lingual dentition (PI. 2)- 

 Triton and Banella are closely allied, but with a difference in the 

 rachidian tooth ; Triton Gutaceum, however, approaches Banella argus. 

 Distorsio (PI. 2, fig 9.) is not sensibly different from Triton. The 

 dentition of the family is unmistakably allied to that of the Cassididie, 

 Doliidai, etc. 



Fossil Genera. 



The distinctness of the following groups is veiy doubtful. 



RANELLINA, Conrad. The genus was never characterized. The type 

 dift'ers from the figui-e in the varices being partially disconnected, thus 

 showing more affinity to Triton than to Banella. 



Hanella Maclurii Conrad . Plate 3, fig. 14. Tertiary; Claiborne. Ala. 



PERSONELLA, Conrad. Genus not characterized. Scarcely a ZJzsforsio, 



but more like a Outturniuin. 

 Distorsio septemdentata, Gabb. Plate :^, fig. ll. Eocene, Texas. 



TRITONOPSIS, Conrad. The type is a water-worn spec.imen, which Mr. 

 Angelo Heilprin, who has examined the shell, declares to be too 

 imperfect to assign to it any reliable characters. Has some resemblance 

 to the section Cabestana, like T. doliariuin L. 



Triton sobalveatus, Conrad. Plate ;), fig. 30. Eocene, Vicksburg. 



TRACHYTRITON, Meek. The generic character appears to be confined 

 to the occurrence of internal varices, marking the former positions of 

 the lip, and which have not been absorbed when growth recommenced ; 

 otherwise very like Priene OregcnensiK = cancellatus. The want of a 

 callus on the upper part of the columella, which Meek makes a distin- 

 guishing character from Priene, also chai'acterizes the P. Oregonensis, 

 young, as described by Mr, Redfield. 



T. VINCULUM, Hall and Meek. PI. 3, fig. 13. Cretaceous, Z)aA;<?</(7i. 



Genus TRITON, Montfort. 



* Animal ol" T. Tritonis, Linn., figured npon Plate 1 (Frontis- 

 piece). Details of the anatomy of the genus will be found in the 

 introductory portion of Vol. II of this Manual, together with 

 figures iijjon the 3d, 4th and (Jth plates thereof. 



Shell oblong, with generally prominent spire, tlie whorls crossed 

 bv a few remote and non-continuous varices ; the columella 



