ORTMANN I TERTIARY INVERTEBRATES. 147 



73. DOSINIA L/EVIUSCULA (Philippi). 



PI. XXVIII, Fig. 7. 



1887 Artemis lcev. Philippi, Tert. Quart. Verst. Chiles, p. 115, pi. 19, f. i. 

 1899 Dosinia Iccv. v. Ihering, in: N. Jahrb. Miner., etc., v. 2, p. 20. 



Shell circular, not much compressed, but comparatively swollen. Pos- 

 terior dorsal margin convex, hardly forming an angle with the posterior 

 margin. Lunula ovate, slightly concave, indistinct. Surface almost 

 smooth, only with very fine and crowded concentric lines. 



Length, 22 mm; height, 20 mm; diameter, 5 (x 2) mm. 



Remarks: Although much smaller than Philippi's and v. Ihering's spec- 

 imens, and more circular in outline, I believe our individuals to belong 

 here, since the characters of the surface agree completely. Philippi gives : 

 L. 50, H. 43, D. 25 mm, and v. Ihering: L. 75, and perhaps up to 85 mm, 

 while our largest is only: L. 24, H. 21.5 mm. 



Our specimens retain the original shell in many places, and show only 

 very fine, concentric, impressed lines, which are quite different from the 

 distinct impressed lines with more or less prominent intervals in D. mcri- 

 dionalis. And further, the character mentioned by Philippi, that the shell 

 is comparatively more swollen than in other species, is also shown in our 

 individuals: a young one, L. 17.5, H. 17, has a diameter of both valves 

 of 9 mm. 



I think the more circular form of our specimens is due to their young age. 



Record of specimens : Mouth of Santa Cruz River, ca. 30 internal and 

 external casts in hard matrix, with remains of the shell adhering. 



Distribution: Patagonian beds of Santa Cruz (Phil., v. Ih.). 



Fam. -TELLINIDsE Desh. 



Gen. TELLINA L. 

 74. TELLINA TEHUELCHA v. Ihering. 



PI. XXIX, Fig. 3. 

 1899 T. t. v. Ihering, in: N. Jahrb. Miner., etc., v. 2, p. 21, pi. 2, f. 4. 



Shell oblong-oval, subequilateral, inequivalve ; left valve convex, right 

 one flat (according to v. Ihering). Apex at about the middle of the 



