CADULUS. 159 



O. GIBBUS Jeffreys. PL 24, fig. 24. 



Shell barrel shaped, gibbous in the middle, whence there is an 

 abrupt slope towards each end ; these are equal in breadth ; it is 

 rather solid, glossy and semitransparent ; sculpture none; color 

 white. Mouth obliquely truncated ; base slightly notched, but not 

 quite perfect. Length 0*1, breadth 0'05 inch. (Jeffreys). 



Bay of Biscay (Travailleur Exp.) and North Atlantic (Porcupine 

 Exp., 1870, Sta. 13). 



Cadulus gibbus JEFFR., P. Z. S., 1882, p. 666, pi. 49, f. 10; Ann. 

 Mag. Nat. Hist. (5), vi, p. 375 (no description). 



Allied to C. ovulum of Philippi, but much smaller and not so 

 oval, and the ends are equal in size. (Jeffr.~). 



C. EXIGUUS Watson. PI. 25, fig. 6. 



Shell very small, short, broad, pinched in and projecting at both 

 ends, very slightly bent, and that almost entirely in front ; very 

 much swollen in the middle, bulging on the concave curve, a little 

 more attenuated behind ; pretty strong, polished, translucent and 

 white, with an opaque white band round the apex. Sculpture none ; 

 mouth large, straight; edge thin and chipped. Apical opening 

 small, straight, chipped, narrowed inside by a minute shelf-like pro- 

 jecting ring. Length 0*076 inch, breadth at mouth 0'016, at broad- 

 est 0-035, at apex O'Ol inch. (Watson). 



Lat. 18 38 f 30" N., Long. 65 5' 30" W. Culebra Island, West 

 Indies, 390 fathoms (Challenger). 



C. exiguus WATSON, Journ. Linn. Soc. London, xiv, p. 528 (1879) ; 

 Chall. Report, Scaphopoda, p. 23, pi. iii, fig. 10 (1885). 



It differs from Cadulus ovulum Phil, in being very much smaller, 

 rounder, and contracted into a tube at either end. (Watson). 



C. OBESUS Watson. PI. 25, fig. 53. 



Shell short, very broad, narrowed at both ends, little bent, and 

 that almost entirely toward the mouth, very much swollen in the 

 middle, and bulging a good deal on the concave curve, a little more 

 attenuated behind, and very slightly laterally compressed (in the 

 proportion of 14 to a little less than 15). It is pretty strong, 

 polished, translucent white, with one, sometimes two, opaque rings 

 near the apex. Sculpture : a few very vague and faint, distant, 

 transverse lines ; mouth rather large, straight ; edge thin and much 



