24 THE VOYAGE OF H.M.S. CHALLENGER. 



middle. Pretty strong, polished, and translucent white, with an opaque band close to 

 the apex. Sculpture ; None. Mouth large, very slightly oblique ; edge thin and chipped. 

 Apical opening slightly oval, small, straight, roughened, narrowed inside by a flat, 

 concentrically puckered, and margined ring, which occupies nearly half its diameter 

 (0*014 and 0'006). The margin (about O'OOl thick) of this ring is formed by the 

 projecting end of a short pipe (about 0"005 long), which passes up into the interior of the 

 shell. L. 0-08 in. B. at mouth 0-02, at broadest 0-047 ; at apex 0-016. 



This species is not only much smaller than Cadulus ovulum, Phil., from the Mediterranean, but is 

 obviously very different in form and proportions. It differs from Cadvlus exigims, Wats., in being 

 much rounder, has no tube anteriorly, is not nearly so elongated posteriorly, and is provided with a 

 distinct posterior pipe. 



