1 54 PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 



Record of specimens : Mouth of Santa Cruz River, i double valve : San 

 Julian, Darwin Station, i double valve; Lake Pueyrredon, base of Ter- 

 tiary, i double valve ; Lake Pueyrredon, 600' above base, i double valve 

 (jun.). 



84. PANOPEA QUEMADENSIS (v. Ihering). 



PI. XXX, Fig. 2. 



1897 Glycimeris qu. v. Ihering, in: Rev. Mus. Paul., v. 2, p. 264, textf. 4. 



Differs from P. regnlaris in the apex, which is situated only a little in 

 advance of the middle of the shell, and in the posterior end's being nar- 

 rower than the anterior. 



Length, no mm; height, 73 mm; diameter, 54 mm; apex at 46 mm 

 (Santa Cruz). 



Length, 83 mm ; height, 53 mm ; apex at ca. 35 mm (Lake Pueyrredon). 



Record of specimens: Mouth of Santa Cruz River, 2 double valves; 

 San Julian, Darwin Station, i double cast; Upper Rio Chalia, i cast of 

 left valve; 30 miles north of upper Rio Chalia, 2 double casts; Lake 

 Pueyrredon, base of Tertiary, i double cast; Lake Pueyrredon, 600' above 

 base, 5 double casts. 



Distribution: Jegua quemada, Suprapatagonian beds (v. Ih.). 



* 



85. PANOPEA PILSBRYI spec. nov. 



PL XXIX, Fig. 7. 



Shell short and high, very convex, with concentric lines of growth. 

 Apex about in the middle of the length, incurved. Anterior end rounded, 

 posterior subtruncate, hardly narrower than the anterior. Ventral margin 

 straight in the middle. 



Length, 79 mm; height, 60 mm; diameter, 22 (x 2) mm; apex at 38 

 mm. from anterior end. 



Remarks: In the comparatively very short and high outline of the 

 shell, with the apex almost in the middle of the length, and the posterior 

 and anterior ends of the shell of about the same height, this species differs 

 from all others mentioned here. 



We possess one good cast, which shows the pallial sinus well preserved. 

 The rest are only fragments, but, as far as can be seen, possess the same 

 characteristic features, especially the short and high outline. 



