277 



CHONDROPTERYGII. 



The second series of the class of fishes, or the Chondroptery- 

 gii, can neither be considered as superior nor inferior to that of 

 the ordinary fishes, for several of its genera approach the Rep- 

 tiles in the conformation of the ear and of the genital organs, 

 while in others the organization is so simple, and the skeleton 

 so much reduced, that we might be excused for hesitating to 

 place them among vertebrate animals. It is therefore a suite 

 somewhat parallel to the first, as the Marsupialia, for instance, 

 are parallel to the other unguiculated Mammalia. 



The skeleton of the Chondropterygii is essentially cartila- 

 ginous ; that is, it contains no osseous fibres, the calcareous 

 matter being deposited in small grains, and not in filaments; 

 hence the absence of sutures in their cranium, which is always 

 formed of a single piece, but in which, by means of projections, 

 depressions, and holes, regions analogous to those in the cra- 

 nium of other fishes may be distinguished. It sometimes hap- 

 pens that movable articulations, which are found in other or- 

 ders, are not met with in this one ; part of the vertebrsB of 

 certain Rays, for instance, being united in a single body. Some 

 of the articulations of the bones of the face also disappear, and 

 the most apparent character of this division consists in the 

 absence of the maxillaries and intermaxillaries, or rather in 



5th. Triangular, without spines. Ost. cubicus, Bl., IS?; — Ost. pundatus and 

 lentiginosus, Schn., Seb., Ill, xxiv, 5; Lacep., I, xxi, 1, or meleagris, Sh., Gen. 

 Zool., V, part II, pi. 172; — Ost. nasus, Bl. 138, Will., I, ii; — Ost. tuberculatus. 

 Will. I, 10. 



6th. A triangular body armed with spines before and behind the abdomen. 

 Ost. cornutus, Bl., 133. 



7th. A quadrangular body, the ridges armed with spines. Ost. diaphanus, 

 Schn., p. 501; — Ost. turritus, Bl., 136. 



8th. A compressed body, with a carinated abdomen and scattered spines. Ost. 

 auritus, Sh., Nat. Misc., IX, No. 338, and Gen, Zool., V, part II, pi. Iviii, 1, and 

 some neighbouring species. 



N.B. The Ost. arcus, Seb. Ill, xxiv, 9, is perhaps a mere variety of the cornutus, 

 and the gibbosus, Aldrov., 561, appears to me to be a badly drawn triqueter. 



