118 



OLD RED SANDSTONE FISHES. 



Quarry, and belongs to the collection of the Geological Survey of Scotland. It is 

 represented in PI. XXVI, Fig. 1 , of the natural size, and shows the form of the 

 dorsal aspect of the body and the greater part of the head. Unfortunately, the 

 head is imperfect in front ; but, allowing for that deficiency, its length would be 

 contained a little more than three times in the total of about seven inches. The 

 posterior part of the carapace appears just a little too narrow in the figure owing 

 to the fact that the absolute flatness of the photograph gives no idea that the 

 cavity of the impression expands a little laterally below the level of the surface of 

 the stone in that region. The ornament of the plates is fine, but scarcely finer 

 than in the specimen from Alves figured in PL XXIII, Fig. 5. 



Another is from Laverockloch Quarry on the same horizon, and is in the 



-'-wgBd.an 



dar. 



y.ar. 



Fig. 60. — Upper extremity of the pectoral limb of Bothriolepis major, fi-oni Scat Craig, magnified by 

 one half. 



Fig. 61. — Ventral aspect of the same specimen, also magnified one half. b. p., brachial process ; 

 d. ar., dorsal articular ; i. ar., internal articular ; v. ar., ventral articular. 



collection of the Royal Scottish Museum, Edinburgh. Here also the head is 

 imperfect in front, but its estimated entire length would be contained less than 

 three times in a total of four and a quarter inches. Now, as the greatest breadth 

 of the carapace is two and three quarter inches, this specimen is proportionately 

 shorter and broader than that from Rosebrae last described ; and, moreover, the 

 posterior median dorsal shows just a trace of carination. Nevertheless, until 

 further information comes to hand, I hardly consider those differences sufficient to 

 warrant the erection of a new species. 



Remarks. — This is the Pterichthys major of Agassiz, a name which, as already 

 remarked (p. 76), has in bygone years been too often "taken in vain" by Scottish 

 collectors, every big fish-plate from the Upper Old Red Sandstone being freely 

 referred to it without further examination. The name was originally given to the 

 proximal plates of a pectoral appendage from the Findhorn, and figured by Agassiz in 



