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THE FOSSILIFEROUS DEPOSITS

branches of natural science, adds an intimate acquaintancewith the fossils of our northern formations, and whose skillin zoophytology the late lamented Dr Landsborough has ac-knowledged in his interesting “History of British Zoophytes.”Further, it is worthy of remark that, just as the naturalistcannot now acquaint himself with all the animals or plantsof Scotland in any single locality, so all the fossil species ofany one formation cannot be exhausted in any one limitedfield or district, but must be sought for in various districtsere the list can be regarded as tolerably complete. The oldDevonian species of fishes, like those of the present day, seemto have had their favourite haunts and feeding or spawninggrounds, and must now be sought for where they congregatedof old. The Diplacanthus striatus, for instance, is one of thecommonest of the Cromarty Old Bed fishes, and the Dipterusand Asterolepis very rare; whereas at Thurso , Mr Dick, afteryears of exploration, never found a single spine of Diplacan-thus, but not a few noble specimens of Asterolepis, and finely-preserved skulls and jaws of Dipterus. And in a neighbour-ing locality, Banniskirk, Dipterus is the prevailing fish, andmay be found by scores. Again, the Old Bed of Caithnessgenerally is poor in specimens of Pterichthys, —the rocks ofThurso have not yet furnished a single specimen ; whereasin those of Moray the genus is not rare ; and in a quarry afew miles to the north-east of Stromness it is more abundantthan any of its contemporaries. I mention these facts toshow how necessary it is to the Palaeontologist who sets him-self to exhaust the organisms of a formation within even asingle country, that he should either be a sedulous traveller,or have a widely-located circle of friends engaged with himas fellow-labourers in the work.

Ho ichthyic species of this Lower formation of the OldBed Sandstone has yet been detected in Scotland to the southof the Grampians . In the great belt of Old Bed which tni-