TAYLOR : VARIATION OF LUrN/EA PEREGRA. 303 



The vars. therinalis and glacialis, in respect to the tenuity 

 of their shell substance, also resemble the van diapliana. 

 Dupuy states that the L. rochi is identical with the var. thermalis, 



Var. lineata Bean. Shell furnished with strong spiral riclges. 



This variety received its name on account of the spiral 

 ridges with which the shell and more especially the last whorl 

 is furnished. The original figure was published in Loudon's 

 Mag. Nat. Hist, Oct. 1834, p. 493. 



Var. marginata Michaud. Shell furnished with a distinct rib near the 

 margin of the outer lip. 



This variety is characterized by the unusual thickening of 

 the outer lip, in such a manner as to resemble what is usually 

 termed an internal rib. The variety labiata Rossm. and tlie 

 variety styriaca are stated by Westerlund to have the same 

 peculiarity. The var. albo-limbata Kuster is ]3robably also 

 identical. The var. a'.bo-inarginata Clessin has for its special 

 feature the pure milk-white apertural margin. 



If, however, the inner margins of the mouth are brown, 

 and not the usual dull whitish or pale-horn colour, we have then 

 the chief character of the variety me.lanostovia of Ziegler and 

 Parreyss. 



When the animal forms two tliickenings or ribs, it is then 

 the variety bilabiata of Hartmann. 



If, however, the calcareous secretion becomes unusually 

 thick upon the inner lip, it is then the variety callosa of 

 Ziegler and Kobelt. 



Var. margaritana Esm. Shell with the interior nacreous or pearly. 



This variety is another modification of this species, in- 

 tended to distinguish an unusually nacreous or pearly appear- 

 ance of the interior of the shell, which peculiarity is made 

 more strikingly visible when the outer surface of the shell 



