MOLLIJSCA OF THE * CHALLENGER ' EXPEDITION. 523 



and having no swelling. From S. tetraschistim, W., it differs in 

 being more elongated, more attenuated behind, and in the 

 character of the posterior opening. 



7. SiPHODENTALIFM EBORAOENSE, W. 



Sept. 7, 1874. Torres Strait, Cape York. 3-11 fms. 3 spe- 

 cimens. 



Shell. — Small, narrow, tapering very gradually throughout ; toward 

 the apex bent, thin, brilliant, translucent and transparent in 

 alternate bands. Sculpture. There are a few remote, irregular, 

 oblique, transverse striae ; in the young shell the whole surface 

 is covered with longitudinal striae, excessively minute (0*0005 

 in. apart), sharp and regular, but which seem very easily rubbed 

 off*, and which disappear towards the mouth. The mouth is 

 round, very oblique, sharp, and thin. The apex is minute, 

 and is broken straight across and somewhat chipped. L. 0*185. 

 B. 0-024, at apex 008. 



Than S. prionotum, W., this is smaller, straighter, but toward 

 the apex more bent, not narrowed at the mouth ; smaller at the 

 apex, and the whole texture of the shell is different. 



Than S. vitreum, S., this is less cylindrical, is not contracted 

 toward the mouth, and is much smaller toward the apex. 



Cadulus. 



1. C. coluhridens, W. 7. C. curtus, W. 



2. C. vulpidenSy W. 7a. C. curtus, var. con^ruens^W. 



3. C. rastridenSy W. 8. C. ohesus, "W. 



4. C. sauridens, "W. 9. C. tumidosus, Jeffr. 



5. C. gracilis y Jeffr. 10. C. exiguus, W. 



6. C. simillimus, "W. 11. C. ampullaceus, W. 



1. Cadulus colubridens, W. 



St. 169. July 10, 1874. Lat. 37° 34' S., long. 179° 22' E. 

 N.E. point of New Zealand. 700 fms. Grey ooze. 1 spe- 

 cimen. 



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

 flattened, swollen near the broader end. The swell, which ia 

 faintly angulated and is at one fourth of the length, is chiefly 



* On two specimens it is barelj traceable, 



