42 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



V. SYSTEMATIC DESCRIPTIONS OF UPPER 



TRIASSIC FISHES. 



" Die Natur ist das einzige Buch, das auf alien Blattern gewissen 

 Inhalt bietet." — Goethe. 



Order CROSSOPTERYGII. 

 Family CCELACANTHID^. 



" Body deeply and irregularly fusiform, with cycloidal, deeply 

 overlapping scales, more or less ornamented with ganoine. 

 Branchiostegal apparatus consisting of an operculum on each 

 side and a single pair of large jugular plates. Paired fins ob- 

 tusely lobate. Two dorsal fins and a single anal; the anterior 

 dorsal without baseosts, the posterior dorsal and the anal with bas- 

 eosts, obtusely lobate. Axial skeleton extending to the extremity 

 of the caudal fin, usually projecting and terminated by a small 

 supplementary caudal fin. Air-bladder ossified." 



As remarked by Smith Woodward, from whose Catalogue the 

 foregoing definition has been taken, the members of this family 

 have perhaps the most remarkable geological range of all known 

 extinct fishes, persisting as they do practically unchanged from 

 the Upper Devonian to the Upper Chalk. " The group is special- 

 ized," says this author, " in the large symmetrical caudal fin, 

 which exhibits a series of supports directly apposed to the neural 

 and haemal arches, equalling in number both these and the over- 

 lapping dermal rays. It is also specialized in (i.) the fusion of 

 the bones of the pterygo-quadrate arcade, (ii.) the reduction of 

 the infradentaries to one, (iii.) the reduction of the opercular 

 apparatus to the operculum on each side and a pair of gular 

 plates, (iv.) the loss of the baseosts in the anterior dorsal fin, 

 and (v.) the ossification of the air-bladder." 



This family, first proposed by Louis Agassiz in the second 

 volume of his " Poissons Fossiles " (1844, p. 168), and after- 

 wards greatly restricted by Huxley in two important memoirs 

 of the British Geological Survey (Decades X and XII, 1861 and 

 1866), is at present understood as comprising not more than six 



