GASTEKOPODA. 



Shell oval, elongated, ventricose, thick ; 

 whorls rounded or rendered angular by the 

 upper portion being channelled ; last whorl 

 much developed. Ornamentation usually of 

 large longitudinal ribs, crossed by numerous 

 striae ; aperture large in the young state, 

 slightly notched in front ; columella rounded ; 

 umbilical groove deep, narrow, but well de- 

 fined. 



Fossil, 8 species. Inferior Oolite — ^Kelloway 

 Rock. England, France, Germany. ''^' '''seiiona. 



Fig. 12 Tarpvrina 



ToRELLiA (Loven), Jeffreys, 1867. 



Dedicated to Dr. Otto Torell, of Norway. 



Type, T. vestita, Jeffreys. Shetland and ISTorway. 



Animal with the produced lips and lingual dentition of 

 (Jajpulus. 



Shell globose, covered with a velvety epidermis ; spire very 

 short ; apex depressed ; aperture roundish ; pillar with a blunt 

 tubercle at its base ; groove internal, scarcely perceptible ; 

 operculum like that of Trichotropis. 



[Family Neritopsidje.] 



Genera : — Neritopsis and Narica with Naticella as a sub- 

 genus (see p. 261). 



[Family Pyramldellid^.*] 



The following genera and sub-genera are additional :— 



Pyramidella. Sub-genus Chrysallida, P. Carpenter, 1857. 



Shell pupiform ; peristone continuous ; edge of lip thin ; 

 columella-plait distinct, though hidden; operculum in the 

 typical species radiately corrugated. 



Distribution, 25 species. E. and W. Indies, Japan, Mazatlan. 



Odostomia. Some of the Mazatlan species have the peri- 

 stone continuous. 



Sub-genera : — Auriculina, Gray. 



Shell having the general aspect of Odostomia, but presenting 

 no vestige of a plait. Mazatlan, 3 species. 



Fossil, 4 species. Tertiary. United States. 



Parthenia, Lowe {Fhalia, Adams). Surface sculptui'ed ; 

 columella plaited. 



Distrihution, 10 species. Mazatlan, Japan. 



* See p. 238. 



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