245 



sition of the bands which mark the progress of growth 

 in the shell, is very different from either of the above- 

 mentioned genera, never being in longitudinal rows or 

 series, but alternating, few in number, sometimes only 

 one on each whorl, and occasionally none except at the 

 opening, which is always terminated by a varix; this 

 indicates that the animal adds to its shell more than 

 a half turn of its circumference at each enlargement ; 

 the varices are never spinous or foliated, though fre- 

 quently plaited or tuberculated. Shell oval or oblong, 

 canaliculated at the base; spire more or less elevated, 

 (and sometimes extremely long, as in the T. varie- 

 gatum, which occasionally attains two feet in length) ; 

 the mouth is generally wrinkled on both sides; aper- 

 ture oblong, and closed by an operculum. 



Triton variegatum 



Triton pyrum 



nodiferum 



cynocephalum 



australe 



tripus 



lampas 



canaliferum 



scrobiculator 



retusum 



Spengleri 



clavator 



corrugatum 



tuberosum 



succinctum 



»•>«-•• vespaceum 



pileare 



chlorostomum 



lotorium 



anus 



femorale 



clathratum 



