ORTMANN ! TERTIARY INVERTEBRATES. 
125 
49. Crassatellites longior (v. Ihering). 
PL XXVII, Fig. 2. 
1897 Crassatella /. v. Ihering, in: Rev. Mus. Paul., v. 2, p. 247, pi. 5, f. 
34, pi. 6, f. 37. 
Shell elongate-triangular, slightly convex, thick. Apex at about of 
the length. Anterior end rounded, posterior produced and narrowed. 
Posterior dorsal margin oblique, forming a blunt angle with the pos- 
terior margin. Ventral margin curved anteriorly, almost straight pos- 
teriorly, forming a distinct acute angle with the posterior margin. An 
indistinct angulation runs down from the apex to the posterior angle. 
Surface marked with shallow concentric furrows. According to v. Iher- 
ing, the ventral margin is crenulated. 
Length, 44 mm; height, 27 mm; diameter, 8 (X2). Attains, accord- 
ing to v. Ihering, almost double that size. 
Record of specimens : Lake Pueyrredon, base of Tertiary ; 1 right valve. 
Distribution: Jegua quemada, Suprapatagonian beds (v. Ih.). 
Affinities : This species resembles C. nietina Conr. (see Whitfield, 1894, 
p. 60, pi. 8, f. 1 1 — 13) from the Miocene of New Jersey, but it is more 
elongated and less convex, and the ventral margin is straight in the pos- 
terior part. A more remote resemblance exists with C. ponderosa Phil, 
from the Navidad beds of Chili, the latter being larger, thicker, and less 
elongate, with the ventral margin arcuate throughout. 
Fain. CARDITIDrE Gill. 
Gen. CARDITA Brug. 
50. Cardita elegantoides Ortmann. 
PL XXVI, Fig. 5 a_c . 
1899 O. e L Ortmann, in: Amer. Journ. Sci., v. 8, p. 428. 
Shell subcircular, slightly oblique, with 18-19 radial ribs, which are 
convex and obtuse, about as broad as the intervening furrows, and nodu- 
lose. Lunula small, oblong. 
