166 PROF, H. G. SEELEY OX SATJRODESMUS ROBERTSONI. 



13. On Saurodesmus E-obertsoni (Seelef/), a Crocodilian Reptile 

 fi-om the Rh.ettc of Linksfield, in Elgin. By Professor H. G. 

 Seelet, F.R.S., F.G.S. (Read January 21, 1891.) 



Linksfield is north of Elgin and west of the River Lossie. The 

 locality was fully described by Professor Judd, F.R.S., in 1873 *, 

 and the strata, previously regarded as Lias and Wealden, were 

 interpreted as a large boulder of Rhsetic beds in Boulder-clay t. 

 Ji number of freshwater shells occur in these beds, associated 

 with land plants, marine invertebrata, fishes, and reptiles ; but 

 very few of the species are identical with those found in other 

 European localities. And, although there is not much room for 

 doubt as to the age, I could have wished the evidence stronger in 

 determining the horizon of the interesting specimen now described, 

 which was found by Mr. A. Robertson, of Inverugie. It appears to 

 be an isolated bone, first noticed nearly fifty years ago by Sir R. 

 Owen in his second report to the British Association on British 

 Fossil Reptiles. " I have been favoured bj^ Mr. Robertson of Elgin 

 with the examination of a Chelonian femur 4| inches in length 

 from a stratum at Linksfield in which remains of Plesiosaurus 

 and Hyhodus occur ; and this femur, though not identical in form 

 with that of any Trionyco with which I could compare it, yet 

 resembles the modifications of the bone in that genus more closely 

 than in Tortoises, Emydians, or Turtles." This guarded deter- 

 mination has sometimes been read as referring the specimen to 

 Trionyx, but it amounts to no more than a statement that the bone 

 is a femur, and probably Chelonian. It was figured in 1842 by 

 Mr. Patrick Duff in his ' Geology of Moray,' pi. v. fig. 10. At that 

 time only the dorsal aspect was seen. It was acquired by the 

 British Museum in 1854, by purchase, from a sale at Stevens's, 

 and registered by the late W. Davies as " ? humerus of a ? Chelonian "J. 

 In 1889 it was removed from the shelly matrix, so as to expose the 

 ventral aspect of the bone. The latest reference to it is in the 

 B. M. Catalogue of Fossil Reptiles and Amphibia, pt. iii. (1889), 

 p. 223, where Mr. R. Lydekker places it after the remains of 

 Chelytherium with the following description : — " The imperfect 

 right humerus or femur of a Chelonian, perhaps referable to this 

 or an allied form .... The head is wanting, and there is no distal 

 groove or foramen. The specimen differs very markedly from the 

 corresponding bone in any existing type." I am not aware o£ 

 evidence which would associate the specimen with Chelytherium, 

 and the association is not discussed. Mr. Lydekker's cautious 

 determination amounts to no more than a belief that, while the 



* Quart. Journ. Geol. Soc. vol. xxix. pp. 135-138. 



t The Eev. Dr. Gordon informs me that he has seen glacial markings on the 

 rock beneath this boulder. 



I In an article on the Dinosauria in the ' Popular Science Review ' for Oct. 

 1879, p. 46, I referred it with doubt to the Dinosauria. 



