70 CLASS XIV. 



In the lips and at the side of the mouth there are also special cartilages, 

 which correspond to the cartilaginous parts of the oral ring in Petromyzon. 



Chimcera L. Body elongate, fusiform. Tail pinnate beloAV, 

 long, ending in a thread. Osseous scutes in the jaws in place of 

 teeth, two on each side in the upper jaw, one in the lower jaw. 

 Mouth situated under the head. Two dorsal fins ; the first armed 

 with a strong spur, situated above the pectoral fins. 



Callorhynclms Gronov., Cuv., Chimcera Cuv. 



Sp. Chimcera monstrosa L., Bloch IcUh. Tab. 124, Cuv. R. Ani., kl. ill., 

 Poiss. PI. 113, fig. 2 ; in the North Sea and the Atlantic Ocean ; — Chi- 

 mcera callorhynchus L., Bloch Syst. Ichth. Tab. 68, Gueein Incoiujr., 

 Poiss. PI. 67, fig. 3, from the South Sea. 



Section III. Ganolepkhti. 



Fins supported by osseous or cartilaginous rays. Skeleton in 

 some osseous, in others cartilaginous. Cranium in part osseous. 

 Dorsal cord persistent in many. Branchige covered by operculum, 

 free. Scales osseous, covered with a glassy substance, shining ; 

 skin sometimes naked. Swimming-bladder, open by a duct to the 

 oesophagus. Caudal fin mostly asymmetrical, with the supports of 

 the rays adhering beneath the spines of the vertebra produced in 

 the direction of the upper margin of fin. Pectoral and ventral fins, 

 the ventrals placed behind the pectorals. 



The fishes united by Agassiz under the name of Ganoids are re- 

 presented in the present age of the world, besides the cartilaginous 

 stm-geons, only by a few osseous fishes, but form a large division of 

 the class, if we take into account the fishes of earHer periods of our 

 earth. We venture to change the name of Ganoids into Ganolepi- 

 doti, and adopt the division in the same sense as that according to 

 which it has been more closely limited by Joh. Mueller. These 

 differ from the osseous fishes in the form of the heart, in the 

 presence of a spiral valve (sometimes rudimentary) in the intestinal 

 canal, in the optic nerves not lying crosswise over one anothei", but 

 being connected at their origin by a chiasma. In the most there is 

 a half branchia in front of the branchial arches on the inner surface 

 of the operculum. 



See J. Mueller, Ahhancl. der Konicjl. Akacl. der Wissensch. zu Berlin, 

 1844, and printed separately, Ueber den Bau und die Grenzen der Ganoi- 

 den. Berlin, 1846, folio. 



