ORTMANN I TERTIARY INVERTEBRATES. 2OI 



Fam. STROMBID^E. d'Orb. 



Gen. STRUTHIOLARIA Lmck. 



131. STRUTHIOLARIA HATCHERI Ortmann. 



PI. XXXIII, Fig. 10' ". 



1899 5. h. Ortmann, in: Amer. Journ. Sci., v. 8, p. 431. 



Shell ovato-pyramidal, spire scalariform. Whorls with revolving ribs, 

 which number 20 to 22 on the last whorl, and are all equal in size and 

 distance from each other. Upper part of the whorls oblique, not canalic- 

 ulate, rendered subangular by a series of 10-11 blunt, conical, subcosti- 

 form nodes. Of the spiral ribs, about 5 or 6 are in the region of the 

 nodes, the rest (14-15) are below the nodes, on the lower part of the 

 whorls. 



Measurements: Height, 22 mm, diameter, 13 mm; another: height, 

 21 mm, diameter, 14 mm. But it grows a little larger, as is shown by 

 a fragment that is 16 mm in diameter. 



Remarks: This species differs from all the other South American spe- 

 cies of the genus in the spiral ribs, which are of uniform size, in the upper 

 part as well as in the lower part of the whorls. In all the following spe- 

 cies there are at least a few ribs on the lower part of the last whorl, 

 which are distinctly and considerably stronger than those on the upper 

 part. Also the small number of nodes, and the suture, which is not 

 canaliculate, serve to distinguish this species. 



' Record of specimens : Punta Arenas, horizon II (lower Magellanian), 8 sp. 



132. STRUTHIOLARIA AMEGHINOI v. Ihering. 



PI. XXXIII, Fig. n". 



1897 S. ameghinoiv. Ihering, in: Rev. Mus. Paul, v. 2, p. 289, textf. 14. 



1900 S. chilensis Ortmann, in: Amer. Journ. Sci., v. 10, p. 380 (non S. 

 chilensis Phil., 1887). 



Shell ovato-pyramidal, spire scalariform. Whorls spirally ribbed, on the 

 last whorl about 20 to 25 ribs, which are very unequal. Upper part of 

 whorls oblique near the suture, not canaliculated, angulated, angulation 

 formed by a series of 12 to 16, rarely up to 18, costiform, conical, blunt 



