Cretaceous Gastropoda, and Pelecypoda from Zululand. 51 
extremely rare and incomplete. It appears to be related to Nilsson's 
Ostrea curvirostris from the Campanian deposits of Sweden, having a 
very similar contom% as well as an acuminate and curved cardinal 
area, and an upper valve exhibiting a more or less quadrate outline. 
The obscure plications just traceable on the best preserved lower 
valve do not, however, appear to be present on specimens from 
Sweden, that is judging from figures and descriptions as originally 
published (Petrificata Suecana Cretaceae, 1827, pi. 6, fig. 5, 
p. 30), or from the subsequent account of the same species as 
presented by Coquand (Monographie du genre Ostrea, 1869, pi. 35, 
figs. 16-22, p. 67). A small Albian Ostrea of very similar shape 
and with a decidedly plicated lower valve, has been collected in 
large numbers at either Haldon or Blackdown (exact locality not 
certain) in Devonshire, which are to be seen in the W. Vicary col- 
lection at the British Museum, but they have not yet been properly 
studied, and still await specific determination ; all that can be said 
is that they show as much relationship to 0. curvirostris as do the 
present valves from Zululand, but again the plicated lower valve 
furnishes the distinction. Finally it may be mentioned that in this 
last character and in its general shape the valves both from Zululand 
and the Devonshire region show a curious resemblance to the 
0. flahellula of Lamarck from the Lower Tertiaries of England, 
Europe, &c. There is always great difficulty in determining so 
variable a shell as an Ostrea, and unless preservation is good and 
both valves are found in contiguity it is of little service for palseonto- 
logical purposes. We are dealing in the present case with only 
isolated valves of mostly narrow and elongate form, but there are 
evidences of other valves showing a more quadrate outline which 
may represent a further species, but again these are too doubtful 
and much too fragmentary for accurate description. It is sufficient, 
therefore, to say that the specimens, now figured and described as a 
new species, show certain resemblances to 0. curvirostris oi Nilsson, 
and that they further appear to be characteristic of the rocks of the 
Manuan River district. 
Locality. — Tributaries of the Manuan Creek. 
Genus EXOGYRA, T. Say, 1820. 
American Journal Science (B. Silliman), 1820, vol. 2, p. 43. 
ExoGYEA CONICA, J. Sowerby. 
Plate II., figs. 8-10. 
Ghama recurvata, J. Sowerby, Mineral Conchology, 1813, vol. 1, 
pi. 26, fig. 2, p. 69. 
