MOLLUSC A OF PORTO RICO. 
361 
Cuvierina columnella Rang. 
Cmrieria columnella Rang, Ann.Sci.Nat., xm, p. 323, pi. xlv, figs. 1-8, 1828, 
Adult shell somewhat vase-shaped; aperture compressed a little and subtriangular, slightly 
expanded at the sides, upper end of the shell decollated, convex, showing the scar of the elongated 
pointed spire. Color milky white. 
Length 10; greatest diameter, 3 mm. 
Mayaguez, Porto Rico, one dead specimen. 
Genus CAVOLINA Abildgaard, 1791. 
Shell inflated, subglobular, thin; ventral face swollen; dorsal face longer than the ventral, drawn 
out in front; aperture compressed and continued as a fissure around each side of the shell. 
Section DIACRIA Gray, 1842. 
Cavolina trispinosa Lesueur 
Hyalsea trispinosa Lesueur, Blainville Diet. Sei. Nat., xxn, p. 82, 1821. 
Hyalse.a trispinosa Sowerby, Conch. Icon., xx. 1878, pi. in, fig. 15. 
Shell compressed, with three strong, straight spines, one on each side at the posterior termination 
of the fissure, and a longer one behind, longitudinally ribbed on the ventral face; dorsal lip slightly 
recurved, ventral lip strongly recurved. Color whitish, nearly transparent, smoky tinted. 
Length, 10; greatest width, 7 mm. 
Off Aguadilla, one dead specimen. 
Section CAVOLINA s. s. 
Cavolina longirostris Lesueur. 
Hyalsea longirostris Lesueur, Blainville Diet. Sci. Nat., xxn, p. 81, 1821. 
Ilyalxa longirostris Sowerby, Conch. Icon., xx, pi. n, fig. 12, 1878. 
Upper face of shell nearly hemispherical, marked with delicate concentric ridges; dorsal face 
longitudinally ribbed, prolonged in front into a long, somewhat folded, depressed beak; lateral spines 
compressed, central spine short, truncated. 
Length, 4 mm. 
Mayaguez, Porto Rico, many dead shells. 
Cavolina uncinata Rang. 
Hyalse.a uncinata Rang, d’Orbignv, Voy. Am. M6rid., v, p. 93, pi. v, figs. 11-15, 1836. 
Shell much swollen ventrally, the surface delicately and regularly reticulated, with fine, con- 
centric ridges in front; dorsal face with three low, radiating ribs, turned downward and nearly evenly 
rounded at the aperture; lateral spines compressed and curved slightly backward, central spine rather 
short, stout, and curved upward. Color pale amber. 
Length, 9; breadth, 6 mm. 
Mayaguez, six dead shells. 
Cavolina inflexa Lesueur. 
Hyalsea inflexa Lesueur Nouv. Bull. Soe. Philom., m, p. 285, pi. 5, fig. 3, 1813. 
Shell elongated, compressed; ventral face but slightly inflated; ventral lip rounded, scarcely pro- 
duced in the center, marked off by a deep sulcus; dorsal face faintly three-ribbed; dorsal lip nearly 
plain, somewhat produced in the center; lateral spines small, turned backward a little; central spine 
long and stout, curved upward. 
Length, 5 mm. 
Mayaguez Harbor, one dead shell. 
Cavolina gibbosa Rang. 
Hyakea gibbosa Rang in d’Orbigny, Voy. Am. M6r., v, p. 95, pi. V, figs. 16-20, 1836. 
Shell moderately inflated, ventral face produced in front into a high, almost sharp ridge, which 
is strongly, concentrically striated, the rest of its surface finely reticulated, its lip but slightly produced; 
dorsal face convex, nearly smooth or having about seven faint, longitudinal ridges; upper lip moderate 
or somewhat produced, turned sharply downward; lateral spines very short, rather near together, 
central spine short, stout, slightly curved upward. 
Length, 9; breadth, 5; breadth across lateral spines, 4 mm. 
Mayaguez Harbor, one broken specimen. 
This is the Hyalsea flavci of d’Orbigny, 1836, and H. gegenbawri Pfeffer, 1880. 
