314 PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 21, 



The tubercles on the scales arranged in transverse close -set ridges 

 over the middle two-thirds of the scale ; above and below the ridges, 

 irregular tubercles; and towards the posterior margin, sinuous 

 tubercular lines. The anterior border of the scale traversed bj two 

 or three fine vertical striae. 



In general form of body this genus comes nearest to Amblypterus, 

 from which the size of the dorsal and anal fins, the character of the 

 ornament, and the proportional size of the scales, distinguish it. 

 From Eurynotus, the relatively larger head and scales, and the tuber- 

 cular ornament are equally marked grounds of separation, while the 

 teeth are in strong contrast with the small conical Lepidoid armature 

 of the jaw in that genus. 



Both species have, as yet, occurred only in North Staffordshire ; but 

 the appearance of several fragments from other districts renders it 

 probable that the genus is not confined to the English coal-fields. 



EuETisroTTJS, Agassiz. 



I have received, through the kindness of Sir P. G. Egerton, the 

 following remarks on this genus, in the form of extracts from letters 

 addressed to him by the late Hugh MiUer, and gladly comply with 

 his wish for their publication : — 



Edinburough, Feb. 3, 1849. 



** Mt Deae Sir, I found, only a few weeks ago, a group 



of palatal teeth of a rounded form, with a slight dimple in the centre 

 of each (which I used to set down as belonging to some Placoid), 

 existing as the palatal teeth of the Eurynotus crenatus of the Coal- 

 measures u Hugh Miller. 



Edinburough, Feb. 17, 1849. 



"I was desirous that in replying to your favour of the 



6th inst. I should be able to send you with my communication a 

 cast of the specimen of Eurynotus crenatus, in which I detected the 

 palatal teeth referred to in my last. The cast which I now enclose 

 is a good one, and exhibits the rounded granules of the creature 

 scarce less distinctly than the original, one of the finest of this species 

 of Ichthyolite which I have yet seen, and which belongs to our Free 

 Church College Museum. The straightness of the line along the 

 back from the head to the point of the dorsal fin seems a striking 

 characteristic, and has, I think, in the general outline a rather 

 pleasing effect. At least, it would not be easy to construct a fish of 

 a breadth so great in proportion to its length, that would be equally 

 handsome, were this line different. Of the teeth, you will find some 

 eight or nine remaining immediately over what seems to be the 

 under jaw, and the rest represented by the little pit-like sockets 

 which they occupied. The original specimen is from a limestone in 

 the neighbourhood of Crail, in Fife, identical in appearance and 

 character with the limestone of Burdie House. 

 " I am, my dear Sir, 



" Very respectfully yours. 

 Sir Phihp de M. Grey Egerton. " Hfgh MilLER. 



