224 PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 



of the last whorl as tubercles continuing downward as ribs, crossed by 

 furrows ( " anfractibus . . . medio tuberculatis, tuberculis transversim sul- 

 catis, in costas subdecurrentibus"), which agrees better with our species 

 than with Philippi's and Moericke's species. If our species should prove 

 to belong really to Sowerby's species, the specific name of Pyruliformis is 

 to be retained, and that of Philippi's species is to be changed. 



Record of specimens : Mouth of Santa Cruz River, i sp. 



Affinities: According to the considerations given above, there is no 

 doubt that the Navidad form F. pyruliformis is very closely allied. The 

 latter has been compared by Moericke with F. burdigalensis Bast, from 

 the Miocene of Europe (see Hoernes, 1856, p. 296, pi. 32, f. 13, 14). 

 This species is remarkable for the Pyrula-\\\Lt form of the shell, and this 

 character is still more strongly expressed in F. pyruliformis as well as in 

 F. torosus. The sculpture, however, is different, F. burdigalensis having 

 only a row of small tubercles, but no costiform tubercles, and no acces- 

 sory rows of tubercles as F. pyruliformis. 



Fam. VOLUTIDA1 Gray. 



Gen. MARGINELLA Lmck. 



153. MARGINELLA GRACILIOR v. Ihering. 



PI. XXXV, Fig. i. 



1897 M. g. v. Ihering, in: Rev. Mus. Paul, v. 2, p. 308, textfig. 18. 



Shell ovato-oblong, subcylindrical, solid, smooth. Spire short, mucro- 

 nate. Upper whorls with a series of indistinct tubercles, wanting com- 

 pletely on the last whorl. Columella with 4 folds. 



Height, 20 mm; diameter, 10.5 mm. 



Remarks: The obtuse tubercles mentioned in v. Ihering's diagnosis are 

 not visible in his figure, and in our individual only very slight traces of 

 them are discernible. This species differs from M, quemadensis and con- 

 finis v. Ih. in the more slender form. 



Record of specimens : Mouth of Santa Cruz River, i sp. 



Distribution: Jegua quemada, Suprapatagonian beds (v. Ih.). 



Affinities: This species, in its external form, recalls M. bella (Conr.) 

 and M. faimula Dall (1890, p. 53, pi. 4, f. 8, 9), the former from the Mi- 



