ORTMANN ! TERTIARY INVERTEBRATES. 1 53 



82. PANOPEA SUBSYMMETRICA (Ortmann). 



PI. XXIX, Fig. 6. 



1899 Glycimeris subs. Ortmann, in: Amer. Journ. Sci., v. 8, p. 429. 

 Very near the preceding species (P. ibari), but more swollen, not so 



much elongated, and posterior end not narrowed. 



Length, 69 mm; height, 45 mm; diameter, 18 mm. Apex at 28 from 

 anterior end. Rel. H. : L. = i : 1.6. 



Remarks: Differs from the following species (P. regularis) in the posi- 

 tion of the apex (nearer to the middle), and the stronger convexity, 

 especially of the posterior part of the shell. 



Record of specimens : Punta Arenas, horizon III (upper Magellanian), 

 i right valve. 



83. PANOPEA REGULARIS (Ortmann). 



PI. XXX, Fig. }"'". 



1900 Glycimeris reg. Ortmann, in: Amer. Journ. Sci., v. 10, p. 371. 

 Shell elongate, convex, with concentric lines of growth and undulations. 



Apex at one-third of the length, incurved. Anterior end rounded, pos- 

 terior subtruncate, not narrower than the anterior. Ventral margin 

 straight in the middle. 



Length, 101 mm (incomplete); height, 61 mm; diameter, ca. 30 mm; 

 apex at 40 mm (Santa Cruz). 



Length, 78 mm ; height, 45 mm ; apex at 25 mm (San Julian). 



'Length, 105 mm (incomplete); height, 75 mm; apex at 31 mm (Lake 

 Pueyrredon). 



Remarks: This species differs from P. ibari: (i) in the anterior and 

 posterior ends of the shell being equally high; (2) in the straight lower 

 margin ; (3) in the situation of the apex. It differs from P. sub symmetric a : 

 in the more anterior apex and less convex shell ; from P. quemadensis 

 in the more anterior apex and higher posterior end. P. nucleus v. Ih. 

 (1899, P- 2 3> pl- r > f- 7). from Santa Cruz, agrees in the position of the 

 apex, but it is considerably narrower posteriorly, and I do not see 

 any traces of the grooves or depressions described by v. Ihering as run- 

 ning down from the apex (these grooves are not visible in v. Ihering's 

 figure). 



