BRITISH FOSSILS. 



Decade X. Plate X. 



CHEIRACANTHUS LATUS. 



[Genus CHEIEACANTHUS, Agassiz. (Sub-kingdom Vertebrata. Class Pisces. 

 Order Goniolepidoti. Family Acanthodei.) Body fusiform. Tail heterocercal. Fins 

 membranous, each supported by a strong spine. One dorsal fin, one anal fin, two pectoral 

 fins, and two ventral fins. The dorsal spine situated above the interspace between the 

 ventral and anal fins. Pectoral spines articulated to two strong coracoid bones. Scales 

 minute. Teeth small, conical.] 



The generic characters of Cheimcanthus are so clearly defined 

 by Professor Agassiz in the "Poissons Fossiles du Vieux Gres Rouge," 

 and the differences between this and the other Acanthodean genera 

 so fully elucidated, that neither amendments nor additions are re- 

 quired notwithstanding the rapid progress of discovery since the 

 publication of this standard work. Three species are therein de- 

 scribed, Cheiracanthus Murchisoni from Gamrie, Cheimcanthus 

 micTolepidotus from Lethen and Cromartie, and Cheiracanthus minor 

 from Orkney. Professor M'Coy has since described two species, 

 Cheiracanthus pulverulentus and Cheiracanthus grandispinus, both 

 from Orkney, the latter being the largest and most striking species of 

 the genus. In consequence of the stimulus given to the exploration 

 of the Old Red Sandstone deposits of Scotland by the meeting of 

 the British Association at Aberdeen in September 1859, localities 

 which had been previously but slightly examined were opened up, 

 and yielded a rich harvest to the scientific labourers in Palaeontology. 

 Amongst others, .the quarries at Tynet Burn were extensively 

 explored through the liberality of the late Duke of Richmond, who 

 employed a gang of workmen expressly for the purpose. Some of 

 the best specimens discovered were forwarded to me by his Grace 

 for examination, and amongst other novelties and many well-known 

 species, I detected a new species of Cheiracanthus, which I have 

 named Cheiracanthus latus. 



