MITCHELL — GLTPTOLEPIS IN THE SANDSTONE OF DURA DEN. 43 
afforded. In tlie meauwhile, without prejudging the question 
whether the fossil before us be referable to a freshwater or a marine 
form, I incline slightly to the former opinion." 
Eemains of scutes of Chelonian reptiles liave, since this specimen 
has been in our hands, been offered for purchase to the officers of the 
British Museum ; but whether they belong to the same species we 
are not in a position at present to hazard an opinion. 
"We may add that M. Hugi has discovered in the Kimmeridian 
beds of Soleure bones of Emys, associated with marine moUusca. 
Pictet suggests that tlieir remains may have been transported by 
freshwater currents. 
As a provisional arrangement, we would prefer to include our 
specimen in the genus Chelys, giving it a characterizing specific 
name in lionour of our friend wlio has so obligingly worked out ita 
relationship to the other reptiles of the interesting family to which 
it belongs. 
ON THE OCCURRENCE OF GLYPTOLEPIS IN THE 
SANDSTONE OF DURA DEN. 
By the Eey. Hugh Mitchell, M.A. 
In his admirable essay on the Devonian Fishes, in the Tenth De- 
cade of tlie Geological Survey, Professor Huxley has clearly indicated 
and described the differences and the resemblances of the genera 
Holoptychius and Glyptolepis. In the interesting woi'k of the Rev. 
Dr. Anderson on ' Dura Den,' in which its exquisitely-preserved 
fossils are described, no mention is made of Glyptolepis. In the 
November part of the ' Journal of the Geological Society of London,' 
Mr. Powrie has called attention to the occurrence of Glyptolepis in 
slabs recently disinterred, for the St. Andrew's Museum, from Dura 
Den. Through the kindness of Dr. Anderson, a slab was presented 
to the Montrose Museum in 1859 ; and it is now apparent from it 
that Glyptolepis is not of rare occurrence at Dura Den, and that 
either this genus has been passed over altogether, or confounded 
with Holoptychius. The fishes in the Montrose Museum are smaller, 
and do not in all points correspond with those described by Mr. 
Powrie, but we think they emphatically demonstrate that the Holo- 
ptycliius FJeminyii must now be denominated Glyptolepis. 
On the slab in the IMontrose Museum there is one line specimen 
of Holoptychius and six specimens of Glyptolepis, not regarding 
fragmentary portions of fishes. At the first glance there is a resem- 
blance in size, in general aspect, and outline, among the fishes. 
Their average length is about nine inches, and their breadth at the 
thickest part of the body nearly three inches. But, on looking more 
closely, we at once discover the characteristic differences of the 
