177 
ROSTELLARIA maeroptera. 
TAB. CCXCVIII. CCXCIX. CCC. 
Spec. Char. Fusiform, smooth ; lip large, nearly 
circular, with a canal extended along the spire, 
beak straight pointed. 
var. /3. has a sinus in the upper part of the 
lip. Tab. 299. 
Syn. Strombus amplus, Brander , 76. 
Rostellaria macroptera, La March . env . 
de Paris. 48. 
Hippocrenes macropterus, Montfort , v. 2, 
p . 523. 
In the young state this shell is highly polished, fusiform, 
with an acute elongated spire whose sides are nearly 
straight and base concentrically grooved; as it advances 
the left lip is considerably thickened and the right lip 
expands until it extends the whole length of the spire, 
and exceeds in width half the length of the shell ; when 
full grown the two lips together form at their upper 
junction a long canal that is variously bent over or 
around the apex of the spire; towards its upper part 
the left lip projects considerably over the other, covering 
and often almost concealing the canal beneath it, and 
then is again reflected towards the spire ; the beak 
projects beyond the lip forming a narrow pointed canal ;‘ 
in perfect shells the last whorl is gibbose and the furrows 
upon its lower part concealed. In some specimens there 
is a deep sinus in the upper part of the large lip, sepa- 
rating it from the canal upon the spire; this is the 
character of var. /3 see tab. 299. 
