ORTMANN ! TERTIARY INVERTEBRATES. 
147 
73. Dosinia l/eviuscula (Philippi). 
PL XNVIII, Fig. 7. 
1887 Artemis lezv. Philippi, Tert. & Quart. Verst. Chiles, p. 1 15, pi. 19, f. 1. 
1899 Dosinia Icev . 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 alrnost 
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. meri- 
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, LI. 17, has a diameter of both valves 
of 9 111m. 
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. TELLINID.E 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 
