162 
CHOANOPOMA §. 2. 
y. Anfractu ultimo paulo longius soluto. (Spec, authent.) 
CycJostoma aculeosvm Adams Contrib. to Concb. N 1. p. 2. * *) 
Habitat in insula Jamaica. 
Obs. Differt a Ch. scabriculo forma magis depressa, decussatione regulari, 
umbilico et operculo. 
2 12. CIi. gpinulosum Adams. 
T. umbilicata, globoso-conica , tenuiuscula, sorclide alba, 
fusco irregulariter strigata et subfasciata, liris spiralibus sub- 
confertis, obtusis, costulisque confertis, acutis clathrata; spira 
conica, plerumque truncata; anfr. (inclusis apicalibus) 5 per- 
convexi, sensim accrescentes , ultimus teres, antice breviter 
solutus; umbilicus mediocris, pervius; apertura circularis, axi 
parallela ; perist. duplex : internum porrectum, striatum, exter- 
num breviter refiexum, radiatum, superne subauriculatum. — 
Diam. maj. 147-2? min. 11, alt. (trunc.) 11 mill. Ap. 6 mill, 
longa. (Mus. Cuming. Spec, authent.) 
Cyclostoma spinulosum Adams Contrib. to Conchol. N. 1. p. 1. **) 
numerous close -set spiral lines, that appear only on the three last whorls 
and are most conspicuous just below the suture; spire with very convex 
outlines ; apex truncate with the loss of two whorls ; three and one half re- 
maining, very convex, with a deep suture; last whorl a little detached fi'om 
the penult whorl near the aperture, but soldered to it by the outer peri- 
treme ; aperture exactly circular, inner peritreme much produced , regularly 
striated on the outside parallel to the edge; outer peritreme finely scolloped 
with the termination of the spiral lines ; umbilicus extending through to the 
truncate apex, and exhibiting all the whorls. Mean divergence 88°; length 
0,55, greatest breadth 0,63, least breadth 0,43 inch. (Ad. 1. c.) 
*) Shell short, globose- conic ; dingy white; with crowded transverse 
thin perpendicular lamellae, which are decussated by numerous thin promi- 
nent spiral lines , with the points of intersection produced into slender spi- 
nes, especially in the angle of the deep suture, the spiral lines appearing 
on the last three whorls ; spire with very convex outlines ; apex truncate 
with the loss of two whorls , three and one half whorls remaining , very 
convex; last whorl .a little detached from the penult whorl near the aper- 
ture, but soldered to it by the outer peritreme; aperture exactly circular; 
inner peritreme well produced; outer peritreme well expanded, scolloped 
and striated as in the preceding ( C . spinulosum ); umbilicus moderately 
wide, extending through the truncate apex The spiral lamella of the oper- 
culum is extremely high and but slightly reflected outwards. Mean diverg- 
ence 77°; length 0,56, greatest breadth 0,6, least breadth 0,38 inch. 
(Ad. 1. c.) 
**) Mean divergence 75°; length 0,55, greatest breadth 0,55, least 
breadth 0,38 inch. (Adams 1. c.) 
