ERATOIDAE 179 



Trivia 7tix Schilder White Globe Trivia 



Southeast Florida and the West Indies. 



% inch in length, globular, pure-white in color. Characterized by about 

 2 2 to 26 riblets. Back with a strong groove interrupting the riblets. Alias 

 T. nivea Gray. This is the largest and most globular of the white species 

 found in the Western Atlantic. It is moderately uncommon. 



Trivia ritteri Raymond Ritter's Trivia 



Monterey, California, to Lower California. 



% inch in length, globular, pure-white in color. Characterized by about 

 15 fine riblets that run over the bottom, sides and back of the shell without 

 being interrupted by a dorsal groove. Uncommonly dredged on gravel bot- 

 tom from 25 to 60 fathoms. 



Trivia califorfiiana Gray Californian Trivia 



Plate 20V 



California to Lower California. 



Vs to just less than K' inch in length, rotund, and characterized by its 

 mauve color, white, slightly depressed crease on the midline of the back, and 

 by the fairly coarse riblets crossing over the entire shell (outer lip with 

 about 15). A common littoral species, often washed ashore with seaweed. 

 Also lives as deep as 40 fathoms. Trivia sangninea Sowerby, a more south- 

 erly species, is larger, deeper purple, without the prominent white streak on 

 the back and with finer, more numerous riblets (outer lip with about 20). 



Trivia soIa?idri Sowerby Solander's Trivia 



Plate 20U 



Catalina Island to Panama. 



% to % inch in length, rotund, and characterized by the strong, raised, 

 smooth riblets running over the lip and up onto the back. Dorsal groove 

 deep, cream-colored and flanked by 8 to 10 cream nodules on each side. 

 Ground color of shell dark purplish brown. Moderately common in the lit- 

 toral zone. 



Trivia radiajzs Lamarck (Lower California to Ecuador) is larger, flatter, 

 and with a brownish spot on the back which discolors the central groove. It 

 is fairly common. 



