TO GEOLOGY. 159 
to the opposite side it descends about the same distance ; 
mouth subovate, rather contracted; outer lip small, thin 
and edged below, above thick and recurved. 
Length 2.2, Breadth .7, of an inch. 
Observations. This curious species of an interesting 
genus, presents characters unknown in any with which I 
am acquainted. Its most extraordinary character is that 
of the deposit, coating the whole of the shell thickly over 
except the lip; this gives it a rude unshapen appearance. 
It ascends and overtops the beautiful spire, and enclosing 
it forms a new apex above. Young specimens present so 
entirely a different aspect as to make it difficult to believe 
they are the same species. They are gracefully formed, 
and the superior part is covered with longitudinal, parallel, 
flexed ribs—fine transverse strize cover the whole exterior 
surface. In this state it closely resembles the young of R. 
eurvirosiris (Lamarck). The figure represents a specimen 
with the deposit removed from the apex, in which state 
they often occur. Having six fossil species from Europe, 
in my cabinet, I am able to make the following compari- 
sons. It differs from the Strombus amplus (Brander), 
(Rostellaria macroptera of Lamarck), in being without the 
great wing which in my largest specimen expands 
beyond and behind the top of the spire. It differs from the 
R. longirostra (Grateloup) greatly in the deposit, this 
species having little more than the columella thickened— 
it differs from the R. columbata (Lamarck), which is thick- 
ened only along the canal terminating near the apex—it 
‘differs from the R. fissurella (Lamarck), which is strongly 
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