THORNY-PINNED FISHES. 119 



lay so thickly side by side, like the feathers in the 

 wing of a bird, that they presented to the water a 

 continuous surface of bone, and the membrane 

 only served to support and bind them together." 



The Cheirolepis literally, scaly hand, but as 

 applied to a fish, signifying scaly pectoral fin has 

 a beautiful representative in this collection. The 

 scales, unlike those in the two last-described 

 fossils, are exceedingly small, and seem to run in 

 minute wavy diagonal lines from the shoulder 

 backwards, and the fins are similarly clothed. 

 This specimen measures exclusive of the matrix 

 fourteen inches and a half in length, and four 

 in diameter. 



Of the thorny-finned order Acanthopterygii 

 perhaps the most common is the Cheir acanthus, 

 or thorny hand. I have found several fore- 

 shortened examples myself of this ichthyolite at 

 Tynet burn, but its precise external form is 

 seldom represented in the fossils, as it is gene- 

 rally more or less distorted ; doubled up, as it 

 were, with its tail almost in its mouth, as if it 

 had expired in agony, and been petrified in that 

 attitude.* Where this occurs, the nodule is 



I am since indebted to Mr. Simpson, of Tynet, for n remark- 

 ably fine specimen of The Chcirarnnthiu, from his own collection, 

 representing the fish in perfect profile. 



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