ACICULIDZ. 307 
Geomelania Jamaicensis, Pfr. in Proc. Zool. Soc. 1845, p. 45; 
Ic. Cyclost. p. 214, t. 30, f.19, 20; Adams, Contrib. to Conch. 
p. 18; Gray, Cat. Cycl. p. 68; Petit, in Journ. Conch. 18851, t. 2, 
f.4; Pfr. Mon. p. 7. 
Hab. Jamaica. 
3. GEOMELANIA MAGNA. 
Shell elongate-conic, whitish, with, on each whorl, about thirty- 
eight rather slender transverse much arcuated ribs ; spire with 
rectilinear outlines ; apex truncate, with the loss of 8 whorls ; 
whorls remaining 63, moderately convex, with a well-impressed 
suture ; aperture ovate, widely and deeply effuse ; labrum well 
expanded and reflected, with the linguiform part at the anterior 
end wide, obtuse, well produced obliquely and laterally; labrum 
well thickened, slightly separated from the penultimate whorl. 
Length 0.65, greatest breadth 0.19, least br. 0.15 inch. (Adams.) 
Geomelania magna, Adams, Contrib. to Conch. n. 6, p. 94; Pfr. 
Mon. p. 8. 
Hab. Jamaica. 
4, GEOMELANIA PROCERA. 
Shell slender, conic-cylindrical, whitish, with, on each whorl, about 
thirty stout prominent acute-edged transverse ribs, which are 
continued nearly to the anterior margin of the aperture ; with 
very numerous microscopic lightly-impressed spiral strize in the 
intercostal spaces ; spire with rectilinear outlines; apex trun- 
cate, with the loss of 7 or 8 whorls; whorls remaining 7-73, 
moderately convex, with a well-impressed suture; aperture 
ovate, widely and deeply effuse; labrum well expanded, reflected 
and thickened, with the linguiform part at the anterior extre- 
mity well produced obliquely and downwards, rather narrow, 
but not acute ; labium well thickened, separated slightly from 
the penultimate whorl. Length 0.63, greatest breadth 0.15, 
least br. 0.13 inch. (Adams.) 
Geomelania procera, Adams, Contrib. to Conch. n. 6, p. 95; Pfr. 
Mon. p. 9. 
Hab, Jamaica. 
5. GEOMELANIA GRACILIS. 
Shell similar to that of G. procera; bat the ribs are much more 
slender and numerous (about forty on each whorl), and are 
more or less inequidistant ; only very slight traces of spiral 
strize can be detected under a magnifier ; the apex is truncate, 
with the loss of 8 whorls; the linguiform part of the lip is 
subacute, and is much produced obliquely and laterally at the 
