8 



BRITISH FOSSILS. 



The Genus C(el acanthus, Agassiz. 



The name Codacanthus was first applied to a genus of fossil 

 fishes by Agassiz, in the feuilleton of his Recherches sur les 

 Poissons fossiles,'' dated March 1836* ; and figures of the frag- 

 ments from the Magnesian Limestone of Durham, to which he 

 applied the title of Ccelacanthus granulatus^ were published in 

 1839, in Plate 62 of the second volume of that work. 



Furthermore, in the systematic catalogue of the fossil fishes 

 in the collections of Lord Enniskillen and Sir Philip Egerton, the 

 family Celacanthes had been established for the genera Ccela- 

 canthus, Holoptychius, and Macropoma, with two additional species 

 of Codacanthus, C. lepturus and C. gracilis, from the Carboniferous 

 formation. 



But no description of these specimens, or diagnoses of the genera, 

 had appeared in 1842, when Count Mlinster published the fifth 

 part of his Beitrage zur Petrefacten-Kunde," containing figures 

 and descriptions of the fishes from the Lithographic slates which 

 he names Ccelacanthus striolaris and C. Kdhleri. 



Count Miinster, however, had already published notices of these 

 fishes in Bronn's " Jahrbuch," for 1842, and had applied the 

 generic title of Undina to them. And he remarks, that if 

 Agassiz' genus Ccelacanthus from the older formations is provided, 

 like Macropoma, with conical teeth, the otherwise very similar 

 fishes from the Lithographic slates would belong to a diiferent 

 genus, for which the title of Undina might be retained. 



With this proviso Miinster continues his description, as 

 follows : — 



" Genus Ccelacanthus, Agassiz.f 



Teeth flat, strongly granulated : scales thin, elongated, rounded off : 

 two dorsal fins : caudal fin very large and broad, vertebral column 

 traversing the middle of it, and forming at its point a second small pencil- 

 like fin. Skeleton, with the exception of the vertebral column, bony ; 

 body elongated. 



" 1. Ccelacanthus striolaris 



I am acquainted with four specimens of this species, all of which were 

 found at Kelheim, on the right bank of the Danube. The largest of 

 them in my collection, measures a foot (Rhenish) fi:om the head to the 

 tip of the tail, and three inches five lines in breadth, without the fins ; 

 the smallest specimen; in which the apex of the head is wanting, is nine 

 inches long and two inches six lines broad. The former is depicted in the 

 second plate, but, since the thoracic ^and abdominal fins are not well 

 preserved in the original, I have supplied these parts in the figure from 

 other specimens. Both specimens, as well as a third, which I have had 

 the opportunity of examining, lie upon one side, and exhibit a slightly 

 convex back and an almost straight ventral line. The head is small, the 

 forehead strongly arched ; the bones of the head, however, are very 

 brittle, and hence are badly preserved. Of the teeth only a few, as well 



* See Count Munster's "Beitrage" Heft, V. 1842. 



f The references to the figures are, for the most part, omitted in this translation. 



