THE VOYAGE OF H.M.S. CHALLENGER. 



3. Cadulus, Philippi, 1844. 

 Species. 



1. Cadulus colubridens, Wats. 



2. Cadulus vulpidens, Wats. 



3. Cadulus rastridens, Wats. 



4. Cadulus sauridens, Wats. 



5. Cadulus gracilis, Jeffr. 



6. Cadulus simillimus, Wats. 



7. Cadulus curtus, Wats. 



7a. Cadulus curtus, var. congruens, Wats. 



8. Cadulus obesus, Wats. 



9. Cadulus tumidosus, Jeffr. 



10. Cadulus exiguus, Wats. 



1 1 . Cadulus ampullaceus, Wats. 



1. Cadulus colubvidens, Watson (PL III. fig. 1). 



Cadulus colubridens, Watson, Prelim. Report, pt. 2, Journ. Linn. Soc. Lond., vol. xiv. p. 523. 



Station 169. July 10, 1874. Lat. 37° 34' S., long. 179° 22' E. N.E. point of New 

 Zealand. 700 fathoms. Blue mud. Bottom temperature, 40°. 



Shell. — Like an adder's fang ; long, sharp, bent, very slightly flattened, swollen near 

 the broader end. The swell, which is faintly augulated and is at one-fourth of the length, 

 is chiefly on the convex curve, but is visible on the concave curve too. From the angula- 

 tion, the curve is very equable in either direction till about two-thirds along toward 

 the apex, where it bends a little more. The shell is thin, brilliant, semi-opaque, white. 

 Scidpture : Very faiut and fine scratches on the lines of growth. Mouth large, oval, very 

 slightly flattened on the ventral side, from which the thin sharp edge is obliquely cut off 

 upwards towards the convex curve. The 'posterior opening is much smaller, nearly round, 

 and the edge is thin and chipped. L. 0"58 in. B. at mouth 0'067 ; greatest - l ; at 

 apex, 0-033. 



This is twice the size of Cadulus gadus, Montague ; but it resembles that in the angulation, 

 which, however, is hera more marked at the summit of the swelling ; its expansion from the smaller 

 end is much more gradual, and its contraction from the angulation to the mouth is more rapid. 



2. Cadulus vulpidens, Watson (PL III. fig. 2). 



Cadulus vulpidens, Watson, Prelim. Report, pt. 2, Journ. Linn. Soc. Lond., vol. xiv. p. 524. 



Station 24. March 25, 1873. Lat. 18° 38' 30" N., long. 65° 5' 30" W. Culebra 

 Island, West Indies. 390 fathoms. Pteropod ooze. 



Shell. — Like the canine tooth of a small Carnivore ; long, sharp, bent, swollen (a little 

 obliquely) toward the mouth. The swelling is greatest on the convex curve, and lies 

 there a little nearer the end (about one-fourth of the length) than it does on the con- 

 cave, where it is at about one-third of the length. This obliquity makes the form a little 

 unsymmetrical. From the swelling the shell contracts more rapidly towards the mouth. 



