Page:American Seashells (1954).djvu/172

122 $1/8$ inch in diameter; spire low, shell solid; deeply and narrowly umbilicate. Aperture circular, pearly within. Ash-white in color. Characterized by heavy cancellate sculpturing which makes the shell appear pitted by rows of deep, squarish holes. Uncommonly dredged from 10 to 25 fathoms. L. cookeana Dall is not this species, as is commonly thought, but is a Cyclostrema.

$1/4$ inch in length, one third again as wide. 4 to 5 whorls angular with the periphery bearing a series of strong, triangular spines which are hollow on their anterior edges. Color white to cream with small, bright-red patches on top of the whorl. Below the main row of spines there is a minor spiral row of smaller spines. Suture channeled. Aperture circular, pearly within. Umbilicus round, deep, and bordered by 3 spiral, beaded cords. Uncommon under rocks.

The form vanhyningi Rehder from Sand Key, Key West, is pale gray-white with most red patches absent. It lacks fine, axial ridges on top of the whorl which are usually present in the typical form. Uncommon.

Arene venustula Aguayo and Rehder (Miami to Puerto Rico) is similar to cruenata, but smaller, much more squat, chalky-white, and with two peripheral rows of blunt spines. The rows are very close to each other. Rare, 20 fathoms.

$1/8$ inch or less, turbinate in shape; 3 spiral rows of neat, tiny beads on the squarish periphery. Suture minutely channeled and bounded below by a spiral row of whitish beads. Top slope of whorls and base of shell ﬂattish. Axial threads on entire shell microscopic and crowded. Umbilicus round, deep, bordered by 7 to 9 distinct beads. Color of shell white to tan with minute specklings of red and/or brown. Commonly dredged from 3 to 100 fathoms.