130 
PATAGONIAN EXPEDITIONS : PALAEONTOLOGY. 
margin slightly concave, forming an indistinct, rounded angle with the 
anterior margin. Anterior, ventral, and posterior margins forming 
part of a regular circle. Beak small. Surface with concentric, elevated 
lines, which are crowded, especially near the apex. Hinge teeth not 
visible. 
Length, ca. 22 mm; height, 21 mm; diameter, 4 mm (x2). 
Remarks: In my preliminary report on the Magellanian beds of Punta 
Arenas, I confounded these shells with Dosinia magellanica (see below), 
a mistake that was due to the fact, that they are imbedded in the same 
piece of rock with the latter species, and had not been worked out of the 
matrix sufficiently. 
This species resembles much the following ( L . promaucana ), but is 
distinguished by the concentric lines, which, in L. neglecta , are more 
crowded, especially toward the apex, and which are more irregular toward 
the ventral margin. L. neglecta seems also to be a little less convex, and 
the lunula — as far as can be seen — is less concave and less distinct. 
Record of specimens: Punta Arenas, horizon II (lower Magellanian), 
1 double, 1 right, 2 left valves. 
55. Lucina promaucana Philippi. 
PI. XXVII, Fig. 4'A 
1887 L. prom. Philippi, Tert. & Quart. Verst. Chiles, p. 181, pi. 24, f. 6. 
1897 L. proin. v. Ihering, in: Rev. Mus. Paul., v. 2, p. 47, pi. 5, f. 32. 
Shell suborbicular, lentiform, posterior dorsal margin almost straight, 
forming an obtuse angle with the posterior margin ; anterior dorsal 
margin slightly concave, forming an indistinct, rounded angle with the 
anterior margin. Anterior, ventral, and posterior margins forming part 
of a regular circle. Beak small. Surface with concentric, rather widely 
distant, elevated lines. Hinge (of right valve) with 2 cardinal teeth, the 
posterior slightly divided ; anterior and posterior lateral tooth small, but 
distinct. 
Our largest specimen (Punta Arenas) measures : Length, 25 mm ; 
height, 22 mm; diameter, 5 (x 2), another one (Paso del Rio Santa Cruz) : 
Length, 21 mm; height, 19 mm; diameter, 5 mm (x 2). According 
to Philippi and v. Ihering it attains the length of 31 mm by a height of 
ca. 28 mm. 
