2O8 PATAGONIAN EXPEDITIONS : PALEONTOLOGY. 



Species of Tritonium offering a similar structure to these two Patago- 

 nian species are found in the so-called "older" Tertiary beds of Austra- 

 lia (see Tate, 1888, p. 116, ff.), but they require further investigation. 



Fam. BUCCINID^. Trosch. 



Gen. BUCCINUM L. 

 138. BUCCINUM (COMINELLA) ANN^E Ortmann. 



PL XXXIII, Fig. 17. 



1900 B. a. Ortmann, in: Amer. Journ. Sci., v. 10, p. 374. 



Shell subfusiform, elongated-oval. Spire long. Whorls 7-8, angu- 

 lated, the angulation with a series of tubercles, 12-14 on tne l ast whorl 

 which are continued downward as irregular longitudinal ribs. Upper 

 part of whorls (above angulation) slightly concave, appressed toward the 

 suture. Exposed part of upper whorls, below angulation, subcylindrical. 

 Whole surface of shell covered with numerous revolving striae, which are 

 somewhat unequal. Last whorl large. Mouth ovate, elongate, upper 

 end subcanaliculate, lower end truncate, and with a short, reflected canal, 

 forming a varix on the columella. Inner lip a. little expanded, thin. 

 Outer lip thin, smooth within. 



Height, 66 mm ; diameter, 30 mm. 



Remarks : The tubercles of the angulation become somewhat irregular 

 on the last whorl, and indistinct near the mouth. The longitudinal ribs 

 are irregular on the last whorl, sometimes two of them starting from one 

 tubercle, sometimes being quite indistinct. This species belongs to the 

 subgenus Cominella. 



The specific name is given in honor of Mrs. Anna Ortmann. 



Record of specimens : Mouth of Santa Cruz River, 4 sp. 



Affinities: This species comes near B. veneris Basterot (1825, p. 47, 

 pi. 2, f. 15) from the Miocene of Southern and Western Europe. The 

 general form is essentially the same, only the canal is a little longer, and 

 the ornaments of the shell are slightly different : in B. veneris the angu- 

 lation has more numerous and more closely set tubercles, and the longi- 

 tudinal ribs are indistinct or wanting. There is no other Bitccinum, to 

 my knowledge, that resembles our species so much as this one. 



