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 (x 2). 



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. promaucanci], 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), 

 i double, i right, 2 left valves. 



55- LUCINA PROMAUCANA Philippi. 

 PI. XXVII, Fig. 4"' 6 . 



1887 L. prom. Philippi, Tert. & Quart. Verst. Chiles, p. 181, pi. 24, f. 6. 

 1897 Prom. 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. 



