ORTMANN I TERTIARY INVERTEBRATES. 223 



152. Fusus TOROSUS Ortmann. 



PI. XXXIV, Fig. i. 

 1900 F. t. Ortmann, in: Amer. Journ. Sci., v. 10, p. 375. 



Shell subturbinate-fusiform. Spire short, rather depressed. Whorls 4, 

 last whorl very large. Surface with numerous fine spiral ribs, which are 

 rather crowded and somewhat unequal, crossed by very fine, squamiform 

 lines of growth. Whorls strongly convex, swollen, with about 7 strong, 

 variciform, longitudinal ribs, which begin at the suture, and become thick 

 and swollen in the middle of the last whorl, attenuating again toward the 

 lower end of the shell. Mouth ovate, continued into a canal of moderate 

 length, which is slightly curved. 



Height, 31 mm; diameter, 20 mm. 



Remarks: In external form this species closely resembles F. pyruli- 

 formis of Sowerby (1846, p. 258, pi. 4, f. 56) from Navidad. I should 

 not hesitate to identify my individual with Sowerby's species, if it was 

 not for the account of the Navidad form given by Philippi (1887, p. 43, 

 pi. 2, f. i) and Moericke (1896, p. 569, pi. 11, f. i, 2). According to these 

 authors, Sowerby's figure is very poor, and both give better figures of the 

 Navidad species (Philippi in an unnumbered figure in the upper right 

 hand corner of plate 2). 



According to these figures, the Navidad species differs from ours in the 

 following particulars : (i) The upper part of the last whorl, as well as the 

 upper whorls, is smooth, the longitudinal ribs not being continued upward 

 to the suture : in our species these ribs continue to the suture, being very 

 distinct on the spire. (2) The last whorl, from the middle downward, is 

 occupied by swollen longitudinal ribs, which are cut up into a number of 

 tubercles, which form spiral rows : in our species these ribs are crossed by 

 fine spiral cords, but are not cut up by them into tubercles. (3) The 

 canal is perfectly straight, while it is slightly curved in our individual. 



I entertain some doubt, whether Philippi's and Moericke's species is 

 really the F. pyndiformis of Sowerby. Sowerby's figure, no doubt, is 

 poor, but his diagnosis applies perfectly to our individual, since he calls 

 the spire "rudis," by which expression he may have intended the rough, 

 tuberculated appearance given to the spire by the upper continuations of 

 the ribs toward the suture, and, further, since he describes the sculpture 



