114 • 



the shouldei' or bend they are oblique ; whereas on the last limb all 

 the ribs are tiansverse. They are always most strongly marked at 

 the point farthest from the aperture, and almost disappear just before 

 reaching it. Thus, in the centre of the penultimate limb the surface 

 mai-kings appear as flattened, band-like, transvei-ee constrictions and re- 

 elevations, at close and regular intervals, and near the bend these 

 gradually pass into oblique, raised and rounded rib-like folds, which are 

 much narrower than the shallowly concave spaces between them. On the 

 last limb the rib-like folds become fainter and more distant, until at last 

 they fade away into a few ii-reguLirly disposed transverse raised strise 

 near the mouth, at a short distance fiom which there is a single, deeply 

 concave, transverse groove or .constriction. In some individuals the 

 surface of the shell and cast of both limbs is also longitudinally and 

 closely striated. 



The largest specimen collected is rather more than six lines wide at the 

 aperture, (from the siphonal to the antisiphoual side) but average 

 examples are not widei' than five lines at the same point. 



The surface of Dijjtyclioctrati Icevis, Gabb, from the "•' Shasta Group" of 

 Cottonwood Creek, Shasta County, California, is said to be" plain, polished 

 and marked only by a few extremely faint undulations," whereas in the 

 present shell the ribs are both numerous and prominent, especially in 

 the central portion of the penultimate limb. 



This distinction may eventually prove to be only of varietal value. 

 but for the present it will be most convenient to give the Vancouver 

 shell a local name, as the rocks in which it is found are of later date 

 than the Shasta Group. 



Baculites Chicoensis, Trask. 



BaculUes Chicoensis, Trask. — Proc. Cal. Ac. Nat. Sc , 1856, p. 85, pi. 2, fig. 2. 



" « Gabb.— Pal. Cal., Vol. I., p. 80, pi. 14, figs. 27, 29 and 29a, and pi. 



17, figs. 27 and 27«. 

 Baculites inornatus, Meek.— Proc. Ac. Nat. Sc, Phil., 1861, Vol. XIII., p. 316. 

 Baculites Chicoensis, Trask ?— Meek, Bui. Geol. & Geogr. Surv. of Terr., Vol. II., No. 4, 



p. 364, pi. 4, figs. 2 and 2a, b, c. 



Vancouver and Sucia Islands, Meek. Lower Shales, Division B, of the 

 south-west side of Denroan Island. Productive Coal Measures, Division 

 A., of the Sucia Islands (ver^;- abundant), and below Dodd Narrows, V. I, 

 J. Eichardson, 1872-75. 



