11 ^ PATAGONIAN EXPEDITIONS: PALAEONTOLOGY. 
Record of specimens : Mouth of Santa Cruz River ; 2 right, 1 left 
valves ; San Julian, Darwin Station ; 1 right, 2 left valves. 
Distribution : Gulf of S. Jorge, Patagonian formation (v. Ih.). 
Affinities: There is a strong resemblance to P. caloosaensis Dali (1898, 
P- 73b pl- 2 9> f- I2 ) from the Pliocene of Florida, but in the latter the 
striae are stronger, more rib-like, and P. caloosaensis approaches in this 
respect more the younger individuals of P. proxinius. 
The Australian representative of this species is: Pecten palmipes Tate 
(1886, p. 105, pi. 5, f. 4, pi. 7, f. 4); it has been found in so called (?) 
Eocene beds of Edithburgh, Yorke Peninsula, and of Aldinga Bay (South 
Australia). 
39. Pecten cf. centralis Sowerby. 
PI. XXIII, Fig. i a ~ b . 
1846 P. centr . Sowerby, in: Darwin, Geol. Observ. S. Amer., p. 253, pi. 
2, f. 31. 
Sowerby figures a left valve. It is characterized by 5 (text, the figure 
shows 6) radial ribs, which are thin and sharp, and separated by broad, 
concave intervals. This character is exhibited in our left valve, but the 
intervals are finely squamulose, without striae, while Sowerby describes 
“numerous rough radial lines.” 
Sowerby did not possess right valves. Our right valve, which was 
found in connection with the left, agrees completely with that of the fore- 
going species (P. pnenuncius). Anterior ear without sinus. 
Both valves are much broken, very delicate, and have been put in a bed 
of plaster, some fragments of the left valve, however, are not in the proper 
place ; I give the figures, as is the present condition of the shell. 
Measurements of left valve : Height, ca. 63 mm ; width, ? 
There remains some doubt whether this is really Sowerby’ s species ; but 
since it comes from one of his type-localities, it may be that it is this species. 
Record of specimens: Port Desire, N. E. side, 1 right and 1 left valve, 
belonging together. 
Distribution: San Julian and Port Desire, one fragment from the first 
locality, two of the latter (Sow.). Sowerby and Darwin (1846, p. 113) 
mention this species also from Santa Cruz. 
