MANUAL OF CONCHOLOGY. 



Family TRITONIDJE. 



Shell with varices, which are either few and irregularly dis- 

 posed ( Triton ) or form a continuous row crossing the whorls on 

 opposite sides (RaneUa). The number of varices does not exceed 

 two to each whorl, whilst in Murex the smallest number is three. 

 Operculinn annular, with sub-apical or central nucleus. Mantle 

 enclosed, siphon straight, foot small. Lingual membrane with 

 teeth in seven rows (3-1-3), like the Doliidse, etc. (The Muricida? 

 have the teeth 1-1-1). The dentition is illustrated on plate 2. 



I have already stated the reasons which induce me to place the 

 Tritonidae in close connection with the Muricidae, yet forming a 

 passage to the Cassidida* and Doliidae, rather than arrange them 

 with the latter groups. See Vol. II, p. 67. 



The Tritonida 1 first positively appeared in the eocene strata; 

 the genus Spinigera d'Orb., from the cretaceous, being now 

 referred, more correctly I think, to the family Strombidae, and 

 Trachytriton Meek, also cretaceous, does not belong certainly to 

 the family. 



Synopsis of Genera. 



TRITON, Montfort. Shell oblong ; spire prominent, whorls with a few 

 remote and non-continuous varices ; columella rough or smooth ; canal 

 recurved, short or long ; outer lip internally crenated or denticulated. 

 More than a hundred recent species have been characterized. 



DISTORSIO, Bolten. Shell subturreted ; whorls distorted ; aperture 

 irregular, contracted, ringent ; canal recurved ; inner lip dilated, 

 lamellar, rugosely plicated ; columella excavated, verrucosely plicate ; 

 outer lip sinuous, internally plicate-dentate. 



