312 CATALOGUE OF PHANEROPNEUMONA. 
18. GEOMELANIA PYRAMIDATA. 
Shell elongate-conic, whitish, with, on each whorl, about twenty- 
eight small obtuse ribs, which, on the last whorl, terminate a 
little below the periphery ; spire with rectilinear outlines; apex 
usually truncate, with the loss of two or three whorls; whorls 
remaining 7 or 8, quite convex, with a deep suture ; aperture 
widely ovate, moderately effuse; labrum rather thin, slightly 
reflected, linguiform part obtuse, moderately produced laterally 
at the lower part of the right side; labium a little thickened 
and reflected. Length 0.32, greatest breadth 0.11, least br. 0.09 
inch. (Adams.) 
Geomelania pyramidata, Adams, Contrib. to Conch. n. 9, p. 159; 
Pfr. Mon. p. 13. 
Hab. Jamaica. 
§ 5. 
19. GEOMELANIA COSTULOSA. 
Shell conic-cylindrical, whitish, with, on each whorl, about forty 
very slender somewhat arcuated transverse ribs, which are con- 
tinued to the margin of the aperture, and which are much 
widened at their bases; with a few inequidistant lightly im- 
pressed very fine spiral striz, which traverse the ribs or are 
obsolete at their edges; spire with rectilinear outlines; apex 
truncate; whorls remaining about 63, quite convex, with a deep 
suture; aperture ovate, widely effuse; labrum moderately 
reflected and thickened, with the linguiform part very obtuse 
and produced laterally in the lower half of the right side; 
labiumwell thickened, very widely detached from the penulti- 
mate whorl, and united to the labrum above at some distance 
from the extremity of the latter. Length 0.37, greatest 
breadth 0.115, least br. 0.1 inch. (Adams.) 
Geomelania costulosa, Adams, Contrib. to Conch. n. 6, p. 96; Pfr. 
Mon. p. 13. 
Hab. Jamaica. 
20. GEOMELANIA STRIOSA. 
Shell conic-cylindrical, whitish, with, on each whorl, about six- 
teen very slender somewhat arcuate ribs, and twenty-five to 
thirty fine spiral strie, which traverse the ribs, but are some- 
times obsolete on their summits; spire with rectilinear out- 
lines; apex truncate; whorls remaining about 7, moderately 
convex, with a deep suture; aperture ovate, widely and 
deeply effuse; labrum well expanded, reflected, and thickened, 
with the linguiform part moderately produced obtusely and ob- 
