362 MARINE INVERTEBRATES 



GENUS Chlorostoma 



This genus is represented in California by several species, the 

 commonest of which is probably C. funebrale a doleful name, no 

 doubt given on account of the jet-black color. 



C. funebrale. The shell is thick and strong, like most between-tide 

 species, which are constantly exposed to the buffeting of the waves. It 

 is to be found in countless thousands upon rocks exposed at low tide, 

 and may be gathered at any time except full flood-tide, like the littorinas 

 and purpuras of the east coast. Within the aperture the surface is 

 nacreous and greenish in tint ; the last whorl is drawn in, like gathers, 

 at the suture. The umbilicus is closed. There is a white nodule at the 

 base of the lip of the columella. Length one half of an inch to one inch. 

 (Plate LXVII.) 



C. brunneum. This species is brown, as its name would indicate, 

 and there is greenish nacre within the aperture. It lives upon kelp, or 

 upon rocks at very low tide. Length about an inch. (Plate LXVI. ) 



GENUS Trochiscus 



T. norrisi. A flattened shell with rounded, dome-like spire and 

 obtuse apex ; a fairly common species. It has a wide, deep umbilicus 

 and a sharp lip. It is of a rich brown color, with dark chestnut about 

 the umbilical region and greenish-white within the umbilicus ; there is 

 a band of dark olive-green about the inner margin of the lip. The shell 

 is about two inches in diameter and of a somewhat greater height. The 

 operculum is multispiral, with a central nucleus, and is shaggy and 

 rough. Like all other trochids, it feeds upon alga?. It is often found 

 upon the beach after violent storms. Found in California, south of San 

 Francisco. (Plate LXVI.) 



GENUS Livona 



L. pica. This large and interesting trochid is a West Indian species 

 which sometimes occurs in Florida. It lives about coral reefs and rocky 

 shoi-es, attaching itself in vast numbers to the rocks. This shell is a 

 favorite refuge for large hermit-crabs. It is a curious sight in certain 

 of the West India islands to see a Livona pica shell scrambling up a tree, 

 looking very much out of place upon the back of some terrestrially in- 

 clined crustacean. When well cleaned it is a beautiful shell, with black 

 wavy lines over a greenish-white nacreous f dation. The animal has 

 a row of waving cirri upon each side of +he mantle, and long, slender 

 tentacles. It is largely used as an article of diet in the West Indies and 

 Central America. (Plate LXVII.) 



FAMILY 



This family is very closely allied to the trochids, the most 

 striking difference being in the operculum, which in the Turbinidce 

 is calcareous and usually smooth and very convex on the outside, 



