W. B. Dwight—Fossils of the Wappinger Valley. 255 
This is one of the most prominent and abundant of the ortho- 
ceratites in the Wappinger Creek valley; it occurs mostly in 
small fragments, sometimes closely crowded together; the 
largest known specimens have an incomplete length of five or 
six inches, implying a complete one of eight or nine inches. 
Several orthocerata of the latter length have been collected 
which are probably referable to this species, but lack of evi- 
dence as to the septa and siphuncle leaves the question at 
present in doubt. Although the specimens here described, and 
many similar ones, appear to belong under “ Cyrtoceras,” yet 
there is reason for doubt on this point. This arises from the 
presence of quite a number of orthoceratites closely resem- 
bling these, as faras can be judged in their imperfect state, but 
which are nearly or quite straight. It is possible that this 
latter group on further examination may disclose a specific 
difference in the shape of the cross-seetion, and especially in 
the rate of increase in the diameter of the shell which seems 
to differ from the taper above described. A local name has 
been assigned in honor of the college in whose vicinity these 
Specimens occur. 
Cyrtoceras ? dactyloides, n. sp. 
Siph 
barely perceptible flattening parallel to the margin: it is on 
the convex dorsal side; and is proportionally large for a Cyrto- 
_ than 2™™", or one-fourth the diameter of the shell at that point, 
_ while at the larger end, its diameter is 3°75™™ or about one- 
third the whole diameter of that portion. This species bears — 
considerable resemblance to Orthoceras sordidum Billings (Can. 
Net ead:G eol., vol. iv, Calciferous group), yet the aus, 
| dian fossil, the type specimen of which, by the kindness 
= 
