162 CHOANOPOMA $. 2. 
y. Anfraetu ultimo paulo longius soluto. (Spec. authent.) 
Cyclostoma aculeosum Adams Contrib. to Conch. N. 1. p. 2. *) 
Habitat in insula. Jamaica. 
Obs. Differt a Ch. scabriculo forma magis depressa, decussatione regulari, 
umbilico et operculo. 
12. €h. spimnulosum Adauis. 
T. umbilicata, globoso-conica, tenuiuscula, sordide 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, antüce breviter 
solutus; umbilicus mediocris, pervius; apertura circularis, axl 
parallela; perist. duplex : internum porrectum, striatum, exter- 
num breviter reflexum, radiatum, superne subauriculatum. — 
Diam; maj. 14'/,, min.^11,'alt. (trunc.) 11 mil. 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 from 
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; umbilieus extending through to the 
truncate apex, and exhibiting all the whorls. Mean divergence 889; length 
0,55, greatest breadth 0,63, least breadth 0,43 inch. (Ad. 1. e.) 
*) 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. l. c.) 
**) Mean divergence 75?; length 0,55, greatest breadth 0,55, least 
breadth 0,38 inch. (Adams l. c.) 
