646 FOURTH REPORT 1834. 



Fossil Fishes. — Dr. Traill exhibited many specimens of the 

 fossil fishes discovered in the slaty flag of Orkney. They are 

 reported to occur in several parts of that gi'oup of islands ; but 

 Dr. Traill only saw them near Smaill in Pomona, about two 

 miles from the northern extremity of the granitic chain. They 

 occur in a quarry about 100 feet above the level of the sea. The 

 quarry is covered by 3 feet of soil and debris ; then we find 

 from 9 to 1 1 feet of solid strata of flag : but no fish appear 

 until we reach the two lowest beds, which are together about 

 2 feet in thickness. The uppermost chiefly contains fishes, of 

 a flattened form, with a granular skin : which appear to be- 

 long to the family Raja. One of these measured 15 inches in 

 length, of which the tail was 6, and the greatest breadth of the 

 body 6 inches. Unfortunately the specimens of these, which 

 Dr. Traill had collected, never reached Edinburgh. The lowest 

 bed of the quarry abounds most with fishes, and from it almost 

 all the specimens exhibited were extracted. These fishes, in a 

 high state of preservation, were carefully examined by the distin- 

 guished naturalist M. Agassiz, who detected among them eight 

 distinct species, five of which were quite new to him, and even 

 belonged to three new genera. M. Agassiz considers the spe- 

 cies of the fish to indicate that the rock in which they occur is of 

 an era prior to the coal formation. The only trace of vegetable 

 remains observed in that quarry was a single leaf of some mono- 

 cotyledonous plant, resembling that of a reed or a Canna. Be- 

 low the fish slate a shining rock occurs, which contains no or- 

 ganic remains. 



Professor Jameson exhibited a fossil Jish, the Cephalaspis of 

 Agassiz, which he had found in the old red sandstone (Forfar- 

 shire) several years ago, long after he had determined that the 

 sandstone of Caithness, Orkney, Shetland, and of the whole 

 tracts of country on the east and west of Scotland were of the 

 same geognostical age. — Mr. Black adder exhibited a fossil fish 

 from Glammis millstone quarry in the same district. 



On the Fossil Fishes of Scotland. By M. Agassiz. 



The high geological antiquity of the greater part of the stra- 

 tified mountains of Scotland gives a peculiar interest to the in- 

 vestigation of their organic remains ; as they lead us to the 

 knowledge of the condition of our planet at a period in regard 

 to which we possess only a few insulated fragments of informa- 

 tion. The mollusca, zoophytes, &c. of these formations have 

 been examined by many, but the remains of vertebrate animals 



