219 
INFUNDIBULUM, Be Montfort , , 2. 186. 
Part of the Genus Calyptrjea, Delamarck , 
animaux sans vertebras^ 1. 70® 
Environs de Paris , 18. 
Gen. Char. Univalve, obconical, hollow beneath, 
spirally twisted; with a central spiral colu- 
mella and a spirally decurrent plate or valve 
within: mouth round, expanded; lip entire, 
sharp. 
The edge of the internal plate generally diverges obliquely 
from the centre towards the edge, near which it bends so* as 
to enter it at a very sharp angle; the lines of growth are 
nearly circular, but placed obliquely. 
If we consider this shell, with De Montfort, as regularly 
spiral, it will be found to consist of a triangular involute 
tube, the inner side of which is wanted to make it complete, 
the outer lip of the aperture forming the whole of the con- 
cave base ; the inner lip extending only to the centre in one 
direction, and not always to the margin in the other. It 
appears most natural to view it as Delamarck and others 
have done, in its relation to Patella and Crepidula, in con- 
formity with which I have formed the -Generic Character. 
Although, in many instances, De Montfort has multiplied 
Genera beyond their natural limits, in separating this from 
Delamarck’s Calyptraea, he has done an acceptable service 
to the student in Conchology, but he has surely gone too 
far on the same road with older authors in removing it to a 
place so near the Trochus. 
