Mr. T. P. Barkas on Ctenoptychius. 351 
specimens lie are of a very fragile character ; and the speci- 
mens themselves are rather obscure in detail, although their 
outlines are well preserved. 
I have seen the specimens in question, and do not remember 
any indications of “‘ Kammplatten” in connexion with them ; 
and as Professor Huxley does not, in his description of the 
fossils, recognize so marked a peculiarity, I inter that the 
inferior surfaces of the specimens are not presented, or that 
the ‘ Kammplatten ” are not present. 
Ophiderpeton has been found in the Northumberland Coal- 
measures by the late Mr. T. Atthey and myself; but the few 
specimens discovered are of small size and quite insignificant 
when compared with the sizes of the alleged ‘* Kamm- 
platten ” that have been found in our local Coal-measures. 
Ophiderpeton was first discovered in Northumbrian Coal- 
measures by Mr. ‘I’. Atthey; and the specimen, which was 
53 inches long, was described by Messrs. Hancock and 
Atthey in the ‘Transactions of the Tyneside Naturalists’ 
Field-club,’ p. 79, pl. v., new series, 1868-70. 
Since that time various fragments have been found, all 
small, and not at all likely to be the bearers of “ Kamm- 
platten”’ 14 inch long, as some of my specimens are. 
The sole evidence of these comparatively large and well- 
marked comb-like forms being portions of Ophiderpeton rests 
on the researches of Professor Fritsch, as the Scottish and 
Northumberland specimens point more to varieties of 
Ctenoptychius than to Ophiderpeton, specimens of which, so 
far as | am aware, have only been found in Northumberland ; 
and those are of insignificant size. 
The specimens discovered by Mr. T. Atthey are not asso- 
ciated with remains of Ophiderpeton. They are five in number, 
and are now in the admirable museum of the Natural-History 
Society, Newcastle-on-T'yne. -The collections of Mr. Taylor 
of Shiremoor, Mr. Simm of Cramlington, and the six 
specimens in my possession are all unassociated with Ophi- 
derpeton ; and the smallness and rarity of Ophiderpeton render 
their association with it at least very improbable. 
Mr. Stock, at page 95 of his paper, credits me with the 
authorship of Ctenoptychius marginalis, and states he has not 
seen specimens thus labelled. The species was named by 
Agassiz; and the species Ctenoptychius unilateralis was 
quoted by my son, Dr. W. J. Barkas, from named specimens 
in my collection, and published by him in the excellent 
papers describing the external appearance and microscopical 
structure of the teeth of Coal-measure fishes, which appeared 
in the ‘Monthly Review of Dental Surgery’ in the years 
