FISSURELLIDAE 



95 



other to form a knobby, cancellate pattern. Dredged occasionally off the 

 Miami area in 35 to 90 fathoms. 



Rimula frenulata Dall 



Genus Rimula Def ranee 1827 



Bridle Rimula 



Figure 3od 



Off North Carolina to eastern Florida and the West Indies. 



Vs inch in length, thin, very dehcate. Anal slit in the middle of the 

 anterior slope of the shell and arrow-shaped. Base elongate-oval. Shell Vs 

 high as long. Sculpture of fine cancellations. Margin finely crenulate. Color 

 translucent-white to cream or rust, generally a deeper shade at the apex. The 

 commonest species of American Rimula, but rare in collections. Dredged 5 

 to 150 fathoms, especially off the Miami area. 



Genus Fimcturella R. T. Lowe 1827 



Puncturella noachina Linne 



Linne's Puncturella 



Circumpolar; south to Cape Cod; south to the iVleutians. 



V2 inch in length, conical, laterally compressed, with an elliptical base. 

 21 to 26 primary radial ribs between each of which are added a smaller, sec- 

 ondary rib farther down. Margin crenulate. Tiny slit just anterior to the 

 apex, and internally it is bordered by a funnel-shaped cup on each side of 

 which is a minute, triangular pit. Color uniformly white, internally glossy. 

 May be collected under rocks at lowest tides in its northern range but also 

 occurs in waters over a mile deep. Common. 



Figure 30. Pucturellas. a and b, Pimctiirella ciicuUata Gould; % inch (Pacific 

 Coast); c, P. galeata Gould, form major Dall; % inch (Pacific Coast); d, Rimula 



frenulata D3.\\; % inch (Florida), 



