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-Mkt 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. VOL UTIDAEL Gray. 
Gen. MARGINELLA Lmck. 
153. Marginella gracilior v. Ihering. 
PI. XXXV, Fig. 1. 
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, 1 sp. 
Distribution: Jegua quemada, Suprapatagonian beds (v. Ih.). 
Affinities: This species, in its external form, recalls M . bella (Conr.) 
and M. faumda Dali (1890, p. 53, pi. 4, f. 8, 9), the former from the Mi- 
