74 
PATAGONIAN EXPEDITIONS : PALAEONTOLOGY. 
globosa is made by Davidson a synonym of M. venosa (Sol.). (Recent, 
Falkland Islands and Tierra del Fuego.) Our specimens differ from M. 
venosa in the small foramen, which is one of the characters in which M. 
lenticularis is said to differ from M. venosa. The other characters given 
by Davidson are : beak more incurved, dorsal valve uniformly convex, 
and size smaller. They are, however, hardly of any value. And further, 
he mentions a difference in the deltidium, but the latter is described in 
M. venosa in almost the identical terms. Therefore, judging from the 
foramen, which is the only reliable character, the Patagonian fossil belongs 
to M. lenticularis, and it agrees surprisingly well with the account of that 
species given by Suess. 
Record of specimens: Pligh bluffs, S. W. of Lake Pueyrredon, 9 sp.; 
Lake Pueyrredon, base ; 34 sp. 
Distribution: Recent, New Zealand (Dav.); fossil: Gulf of San Jorge, 
Patagonian formation (v. Ih. ) ; Oligocene (Oamaru), Miocene (Pareora), 
and Pleistocene of New Zealand (Suess, Hutt.); Oligocene and Miocene 
of Chatham Islands (Hutt.). 
Gen. TEREBRATELLA d’Orb. 
18. Terebratella dorsata (Gmelin). 
PL XHI, Fig. 7“T 
1864 Terebratella dorsata Suess, in: Novara Exp. Geol., v. 1, p. 57, pi. 
14, f. 6. 
1873 T. d. Hutton, Cat. Tert. Moll. Ech., New Zealand, p. 36. 
1880 T. d. Davidson, Challenger Brach., p. 44, pi. 4, f. 4. 
1887 T. d. Davidson, in: Trans. Linn. Soc., ser. 2, v. 4, p. 75, pi. 14, f. 
9~ l 9- 
1900 T. d. Ortmann, in: Amer. Journ. Sci., v. 10, p. 378. 
Shell very variable in shape, but mostly transversely-oval, wider than 
long. Valves moderately convex, ribbed or (rarely) smooth. Dorsal 
valve with a median sinus, ventral valve with a corresponding fold. Beak 
produced, slightly incurved and truncated by a rather large, circular for- 
amen. Beak ridges sharply defined. 
Length, 44, 43, 38, 31, 31, 28 mm. 
Width, 36, 45, 40, 26, 29, 22 mm. 
