[WHITEAVES] PALLISER’S CRETACEOUS FOSSILS 113 
INOCERAMUS. (Species uncertain.) 
Plate I. 
In addition to the foregoing, there are in the collection four speci- 
mens which the writer is unable to identify, but which are probably 
referable to one species of Znoceramus. All four are very imperfect, but 
the least so is a specimen about eight inches in its maximum height and 
not quite seven in length, labelled “No. 19, Znoceramus Nebrascensis, 
Comox, Vancouver's Island, and Nanaimo River, Dr. Hector, collected 
by Mr. Mackay.” This specimen, which is represented two-thirds the 
natural size on Plate I., is compressed convex, and quite as much com- 
pressed proportionately upon the umbones as upon any other part of the 
shell. Its anterior side is very short and comparatively narrow. Its pos- 
terior side, which is much expanded vertically, both above and below, is 
highest behind the midlength, and subtruncated above. Its hinge- 
line is rather long, and its sculpture consists of low but distinct 
and regularly arranged concentric undulations or plications, and close- 
set and nearly equidistant incremental striæ. Most of the nacreous layer 
of the test is preserved on the right valve of this specimen, but on and 
around the umbo and beak the whole of the test is worn away. In the 
part upon which the test is preserved, about twenty concentric undula- 
tions can be counted. The general outline of this specimen is not very 
unlike that of three very large examples of Znoceramus Sagensis, var. 
Nebrascensis, from the South Saskatchewan River, opposite Swift Cur- 
rent Creek, in the Museum of the Geological Survey of Canada, but in 
each of these the umbones are very tumid and the concentric undulations 
distant, irregularly disposed and almost obsolete. 
Two other specimens from the same locality are labelled ‘: Jnocera- 
mus Crippsii,’ and the more perfect of these is the No. 17 of the list of 
specimens on page 242 of Capt. Palliser’s report. It is a large and well- 
preserved left valve, with about one-third broken off at the posterior end. 
It has much the same shape and style of sculpture as the specimen 
labelled Inoceramus Nebrascensis, but the concentric plications of the for- 
mer (which are twenty-eight in number) are more prominent and acute 
in the umbonal region, where they are crossed by numerous fine radiating 
linear ridges. The fourth specimen is very imperfect, and its surface 
markings are almost obliterated by weathering. 
Arca VANCOUVERENSIS, Meek. 
Arca Vancouverensis, Meek. 1857. Trans. Albany Inst., vol. iv., p. 40. 
Grammatodon ? Vancouverensis, Meek. 1876. Bull. U. S. Geol. and Geogr. Surv. 
Terr., vol. ii., No. 4, p. 356, pl. 3, figs. 5 and 5a. 
One small but characteristic example, thirteen millimetres and a-half, 
or a little more than half an inch, in maximum length, labelled ‘‘ No. 43, 
Sec. IV., 1895. 8. 
