342 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Against the third fissure the secondary strata abut for a height of 

 20 feet, the upper part being covered by the disintegrated rock. 



[The Rev. Mr. Gordon has given the author's subsequent description of the 

 conglomerate and other beds of this division of the series, at pp. 31-33 of his 

 Memoir.] 



Fossils of the Central Division of the Old Med Sandstone. — The 

 fossils consist of scales, most of which have a strong bony structure, 

 and a tuberculated or ridged surface of enamel, — teeth of several 

 kinds, — fragments of jaws with teeth or sockets, — ^vertebrae and other 

 bones of fish, — and ichthyodoruHtes ; almost the whole having been 

 more or less injured previously to their being enveloped in the con- 

 glomerate. Besides scales of the Holoptychus Nohilissimus, many of 

 the other fossils are identical with those obtained from Scat-craig, near 

 Elgin. The scales of the Holoptychus Nohilissimus are well known 

 to occur abundantly at Clashbinnie in Perthshire, near the northern 

 shore of the estuary of the Tay, and in the Old Eed Sandstones of 

 Fifeshire ; from which it may be inferred that those strata belong to 

 the same epoch ; but, as no good natural sections of these rocks, ex- 

 hibiting the succession of the inferior beds, can be obtained, it is 

 important that the identification should not depend on the remains 

 of a single species, which is stated to occur also in the upper division 

 of the system (' Silurian System,' pp. 137 and 601), and in strata 

 directly below the coal in Fifeshire (Edin. Journ. of Natural and 

 Geographical Science, No. 2 ; and Edin. New Phil. Journ. July 1833). 



The drawings of the most remarkable fossils from the Findhorn, 

 &c. will aiford the means of a more extensive comparison, the results 

 of which cannot be unimportant. I am already enabled, through 

 the kindness of Mr. Noble, to identify portions of the beautiful 

 ichthyodorulite (figs.* 1 and 2, drawing 33) found at Clashbinnie, 

 with fragments from the Findhorn and from near Elgin f. The 

 convex bony scale (fig. 4, drawing 20) also appears to be the inter- 

 nal surface of that figured by Dr. Fleming in the ' Edinburgh Journal 

 of Natural and Geographical Science,' fig. 3, in which the engraver 

 has failed to represent its arched pent-roof form seen in the specimen ; 

 and I observed an impression of the same kind in the quarry of 

 Clashbinnie, which was unfortunately destroyed in attempting to 

 remove it. Some additional observations on the figured specimens 

 will be added in the form of an Appendix to this paper J. 



On attentive examination of all the specimens from Burdiehouse 

 to which I could find access in Edinburgh, and of the fine collection 

 from the same place in the possession of Mr. Eobertson, of Inverugie 

 House, near Elgin, I failed to discover a single specimen that could 

 be identified with any of the fossils of the central division of the Old 



[* These drawings do not accompany the MS. — Edit.] 



t It will be observed in this important specimen, that scales of the Holo'ptychus 

 Nobilissimus are found along with the ichthyodorulite ; but from this no con- 

 clusion can be drawn as to their having belonged to the same animal, these 

 scales being so abundant in this quarry as to be mixed in every block. 



[I This intended Appendix, relating to the palaeontological evidences, was 

 never prepared.^EDiT.] 



