432 ME. J. W. DAVIS ON A NEW SPECIES OF CCELACANTIIUS 



also pointed, is in juxtaposition with the ray ; but there is no appearance of bifurca- 

 tion on the part of the latter. The terminal extremity of each ray of the caudal fin is 

 divided into numerous little ossicles by transverse joints, as in the case of those of the 

 other fins. The vertebral prolongation extends to a varied extent in different specimens 

 beyond the first caudal fin : in the specimen now figured it terminates with a slightly 

 rounded extremity, coequal with the length of the fin-rays ; it is enclosed in enamelled 

 scales quite to the end, from which a number of small rays expand to form the second 

 caudal appendage. The number of rays is not easy to determine, but there are at least 

 twelve of them. In a second specimen, not so large, and apparently pertaining to a 

 younger fish, the vertebral continuation extends an inch beyond the termination of the 

 major fin ; its upper and lower surfaces are provided with short fin-rays, and the second 

 caudal fin extends from its extremity, as in the previously described example. 



A portion of the suspensory apparatus is represented by the hyomandibular bone on 

 PL XLVII. fig. 3. There are also other bones whose position and function cannot be 

 satisfactorily ascertained. 



The air-bladder was large, and extended from a position immediately behind the pec- 

 toral arch a distance of 7 inches, to a point immediately under the second dorsal fin. Its 

 depth is about 1 inch. It presents the appearance of a dull, semi-lustrous body, breaking 

 with an irregular fracture, and capable of division into a large number of very thin layers. 

 The latter are semi-transparent, something like thin layers of shellac. Under the micro- 

 scope, no very decided characters can be detected ; the layers do not present the appear- 

 ance of osseous structure, but perhaps resemble as much as any thing the chitinous layers 

 of the dermal covering of some insects. The outward appearance is well represented by 

 the artist on PL XLVL, extending along the ventral portion of the specimen over two 

 thirds its length, and on PL XLVIII. fig. 1 by an oval mass between the pectoral fins, 

 where the scaly covering of the fish has been removed. The structural divisibility into a 

 number of layers appears to indicate that the air-bladder consisted of an outer chamber 

 or sac, divided into a considerable number of compartments by longitudinal septa, these 

 also being, in all probability, subdivided by transverse partitions, which, however, have 

 not been distinguished in the fossil state. 



The species of Coelacanthus now described is from the Cannel Coal in the Middle Coal 

 Measures at Tingley, in the West Hiding of Yorkshire, and with it have been found a 

 number of other fish-remains. In a paper read before the Geological Society, and published 

 in the Quarterly Journal of the Society for Pebruary 1880 *, a detailed description of the 

 stratigraphical position of the Cannel Coal, as well as the manner of its occurrence, is 

 given. In several respects this species possesses distinctive features, which exclude it 

 from either of those described by Agassiz (' Poissons Possiles,' vol. ii. p. 170), or from 

 those which arc described, or whose descriptions have been amplified, in the compre- 

 hensive treatise by Prof. Huxley in the Memoirs of the Geological Survey (decade xii.). 

 The most important characters exhibited by the species now described, which I propose 



* Quart. Journ. Geol. Soc. vol. xxxvi. p. 50. 



