104 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 7, 



Devonian Reptile, which a patient investigation of the specimens has 

 enahled me to detect ; the details have been worked out by the aid 

 of models of those bones that have left distinct imprints, and by this 

 method the form of the dorsal aspect of the neurapophyses, and of 

 the bodies of the vertebrae, the femora, &c., as represented in PI. IV. 5, 

 were determined. 



On the accuracy of the descriptions the palaeontologist may rely, 

 for they have been drawn up with due caution and are faithfully re- 

 corded ; but the following observations on the probable affinities of 

 the original animal are offered with much deference, and as mere ap- 

 proximative inferences, the true value of which the discovery of a 

 skeleton, or even of detached bones, will sooner or later determine. 



The structure of the skeleton, so far as it is disclosed by the spe- 

 cimens submitted to my examination, indicates a pecuhar type of 

 reptilian organization, in which, as in numerous other extinct forms 

 of this Class, osteological characters are associated, which in existing 

 oviparous quadrupeds are restricted to distinct orders or genera. 

 Such anomalies (as our preconceived archetypal notions lead us to 

 regard them) are continually presented to the palaeontologist, and 

 often embarrass his attempts to interpret the relics of beings whose 

 races have long since been swept from the face of the earth. 



The skeleton from Elgin exhibits lacertian characters with batra- 

 chian modifications. From the mutilated condition of the imper- 

 fectly exposed cranium, the feeble imprint of the lower jaw, and the 

 uncertainty as to the mode of implantation of the teeth, no conclusive 

 opinion can be formed as to the construction of the skull ; the oval 

 or oblong form of the head may belong either to a Lizard, or an 

 aquatic Salamander. In the length and characters of the ribs, the 

 situation of the pelvis, and the well-developed limbs, the fossil exhibits 

 lacertian or varanian affinities ; but the apparent structure of the 

 neural arch with its small spinous process, and the horizontality of 

 the articular surfaces of the zygapophyses, and the shape of the'im- 

 pression left by the pelvic arch, are suggestive of batrachian charac- 

 ters ; and in regard tO the extent of the ribs, the fact that in the 

 Pleurodeles the costal processes are not rudimentary, as in other 

 batrachians, renders that feature less decisive. 



In the absence of any certain knowledge of the essential characters 

 of the cranium, jaws, and mode of dentition, and with no traces of the 

 bones composing the pectoral arch and feet, and with but faint indica- 

 tions of the structure of the pelvis, I cannot presume to refer the fossil 

 reptile to any existing order. The difficulties which beset the deter- 

 mination of the natural relations of extinct reptilians, of which even 

 the skull, teeth, and jaws, and many other parts of the skeleton, are 

 known, is strikingly exemplified by the fact, that at the present time 

 the Labyrinthodonts, which in England are generally considered to be 

 true batrachians, are regarded as saurians by many eminent foreign 

 palaeontologists (Von Meyer, Plieninger*, Pictet, &c.) ; and the 



* The Labyrinthodonts are divided by these authors into three genera, viz. 

 Mastodonsaurus (of Jager) ; Capitosaurus, and Metopias. See ' Beitrage zur Pa~ 

 leontologie Wurtembergs.' Stutgard, 1844.^. 



