1870.] HANCOCK AND HOWSE—MARL-SLATE PROTEROSAURI. 565 
4. On Prorerosaurus SPENERI, von MryeErR, and a new species, 
ProrERosauRus Huxteyi, from the Mari-staTe of MippERIDGE, 
Durnam. By Asany Hancock, Hsq., F.L.S., and Ricwarp 
Howss, Esq. 
(Communicated by Prof. Huxley, F.R.S., F.G.S.) 
(Puares XXXIX. & XL.) 
In the preceding paper it has been stated that the requirements of 
a railway company for increased accommodation of their traffic, and 
the continuous indefatigable exertions of our friend Joseph Duff, 
Ksq., to enlarge the knowledge of the Marl-slate fauna of Durham, 
have led to the discovery of some fossil remains which are certainly 
the most interesting paleontologically of recent acquisitions. These 
consist of a considerable portion of the skeleton of that earliest- 
recorded and still oldest-known reptile, Proterosaurus Spenert, v. 
Meyer, and also in close association with it of the greater portion 
of the skeleton of a smaller species, for which we propose the name 
Proterosaurus Huxleyi. Through the obliging kindness of Mr. Duff 
these specimens have not only been placed in our hands for descrip- 
tion, but have also been added to the collection of the Natural- 
History Society of Newcastle, Durham, and Northumberland. 
Perhaps we may be allowed to reflect that in England we have 
now arrived, after the lapse of more than a century and a half, at 
the same point of paleontological discovery, bathymetrically con- 
sidered, which was attained in Germany in the year 1706 through 
the intelligent observations of a learned physician of Berlin, whose 
name has been properly attached to this earliest discovered reptile ; 
and also to consider this fact, that after the expiration of 164 years, 
and notwithstanding the exertions and multiplication of observers 
and enlarged fields of inquiry, these reptilian remains, described by 
Spener and compared by him to the Crocodile and Lizard, still con- 
tinue to be the highest organisms up to this time recorded from the 
paleozoic rocks. And thus this discovery, though it increases our 
knowledge of the geographical distribution of ancient reptiles, adds 
nothing to our knowledge of their bathymetrical range, if we admit, 
as is generally done, that the English marl-slate was contempora- 
neous with, or deposited about the same geological period as, the 
German Kupferschiefer. 
For the history and description of more complete specimens we 
must refer to the classical monograph of Hermann von Meyer, 
‘ Fauna der Vorwelt—Saurier aus dem Kupferschiefer der Zechstein- 
formation.’ 
The geological position in which these reptiles were found has 
already been described in a former communication, so that it is 
unnecessary to repeat it here, further than to state that they were 
associated in the marl-slate proper on the same stratigraphical 
horizon with such fishes as Flatysomus, Paleoniscus, &e. 
The two specimens which we are about to describe were much 
obscured in the matrix; but by the skilful aid of Mr. Thomas 
Atthey the whole of the bones have been perfectly developed at the 
