GASTEROPODS 361 



GENUS Calliostoma 



This genus is better represented on the Pacific coast of the 

 United States than upon the Atlantic. It comprises a series of 

 niarvelously beautiful shells, often exquisitely colored. They 

 are regularly conical or pyramidal in shape, with flattened bases. 

 One never tires in the search for calliostomas. They are not com- 

 mon enough to cause one to lose interest, and whenever a good 

 specimen is captured it seems as though one had found some gem 

 cut and polished by nature's skilful hand and prepared for a 

 place of honor in the cabinet. 



C. occidentale. The only species of this genus found on the north- 

 east coast. It is larger than Margarita cinerea, but somewhat resembles 

 it. It is shining nacreous within and without, and has strong 

 revolving ribs, the upper one on each whorl often being 

 broken into a circular row of white dots. The lip is crenu- 

 lated. This very pretty species is not likely to be met with 

 upon the shore, but may be dredged in shallow water on 

 gravelly bottoms along the Maine coast. Height about 

 one half of an inch. 



C. jnjubinum. A species which occurs in the waters of Florida. 

 Its form is almost that of a true pyramid. The sutures can scarcely be 

 distinguished. The shell is marked by brown and purplish-red spots on 

 a white background, and has numerous revolving ribs broken into rows 

 of white dots like little glazed beads. The umbilicus is funnel-shaped 

 and wide. In Tampa Bay this shell is frequently found on sponges, and 

 may sometimes be gathered on the beach after storms, even as far north 

 as Hatteras. There are as many as twenty species of this genus in Ameri- 

 can Atlantic waters, but they are either rare or have deep-water stations. 



C. annnlatum. A remarkable species of Calliostoma, found in Cal- 

 ifornia. The whorls are adorned with revolving rows of raised dots, and 

 the sutures are frescoed in exquisite purple. This beautiful species lives 

 upon seaweed, and on pleasant days comes to the surface of the water. 

 It can then be collected from a boat by drawing in quantities of sea- 

 weed. It is very unlikely that the collector will ever find a specimen 

 upon the beach, for the shell is too fragile to withstand the rough han- 

 dling of the waves. Length one inch. 



C. canaliculatum. The largest member of this genus to be found 

 in American waters. It resembles the last species in form, but lacks the 

 purple sutures. The revolving ribs are very numerous and prominent. 

 There is no umbilicus. Length one to one and a half inches. Found on 

 the Pacific coast. 



C. costatum. A heavier shell than the preceding, with somewhat 

 more rounded whorls. Reddish-brown in color ; numerous revolving 

 ridges ; no umbilicus ; about three quarters of an inch in length. It is 

 found in rocky places, and sometimes in considerable numbers, just at 

 low-tide mark. Found in California, 



