112 Proceedings of the Loyal Physical Society. 
occasionally occurring in transverse bands, three or four being 
in apposition in a row back to front. 
Doliodus problematicus (A. S. Woodward). 
Diplodus problematicus, A. 8S. Woodward, op. cit., p. 2, pl. i., fig. 2. 
Only a single specimen of this curious tooth was at Mr - 
Smith Woodward’s disposal, and that, too, only exhibiting 
the crown and denticles, being destitute of the root. The 
cusps certainly resemble those of Dzplodus in form and 
arrangement, but the peculiar form of the base, which is 
well shown in many of the specimens now before me, is very 
different, and necessitates the institution of a new genus, 
which, on account of the deceptive appearance of the first 
described example, I propose to name Doliodus.1 
Instead of the thick, solid base of Diplodus, we have here 
a broad thin plate, convex anteriorly and above, concave 
posteriorly and below, to the upper margin of which the 
crown is attached. The type specimen has only one inter- 
mediate cusp, but their number may vary from-one to three 
or even four. 
In connection with the generic separation of this form of 
tooth from Diplodus, Ag., it is interesting to observe that, 
although during his last visit to Canada Mr Jex obtained a 
large number of these teeth, not one example of a Pleuracanth 
spine has occurred in the same beds. I therefore doubt its 
being even referable to the family Pleuracanthide. 
? Cheiracanthus costellatus, sp. nov. 
Several detached spines and one fish wanting the head 
constitute the remains of this interesting species, which are 
contained in the present collection. 
The fish measures 4 inches in length, but it is so distorted 
and shortened up that its real dimensions and contour cannot 
be determined. Six spines are shown, which I interpret as 
two pectoral, two ventral, one dorsal, and one anal. The 
1 Gr. Addcos, a deceiver. 
