CHONDROPTERYGIANS. 237 



jaws is armed with ten or twelve conical teeth. The external branchial 

 aperture is a mere slit furnished with a cutaneous lobe, but internally we 

 find an operculum and six rays. Both the pelvis and ventrals are want- 

 ing, and there are but a single dorsal and ventral, both small. 



They have but little flesh ; their liver, however, is large, and produces 

 much oil. Their stomach is membranous and large ; some of them are 

 considered poisonous. 



They may be divided according to the form of their body and the spines 

 with which it is armed; we are not certain, however, that there is not, in 

 this respect, some sexual difference*. 



The Second Series of the Class of Fishes, or the 



CHONDROPTERYGIANS, 



Can be considered neither as superior nor inferior to that of the ordinary 

 fishes, for several of its genera approach the Reptiles 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 vertebrated animals at all. They 

 therefore constitute a series somewhat similar to the first, as the Marsu- 

 pialia, for instance, bear a resemblance to the other unguiculated Mam- 

 malia. 



The skeleton of the Chondropterygians is essentially cartilaginous; 

 that is, it contains no osseous fibres, the calcareous matter being depo- 

 sited 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 cranium of other fishes may be distinguished. It sometimes 



* 1st. A triangular body without spines. Ost. triqiteter, Bl. 130; — Ost. concate- 

 nate, Bl. 131. 



2nd. A triangular body armed with spines behind the abdomen. Ost. bicaudalis, 

 Bl. 132;— Ost. trigonus, Bl. 135. 



3rd. A triangular body armed with spines before and behind the abdomen. Ost. 

 quadricornis, Bl. 134. 



4th. Triangular, the ridges armed with spines. Ost. stel/ifer, Sehn. 97; the same 

 as the Ost. bicuspis, Blunemb., Abb. 58. 



5th. Triangular, without spines. Ost. cubicus, Bl. 137; — Ost. punctatus and lenti- 

 gbwsus, 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. tuberculatum, 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, Schu., 

 p. 501; — Ost. turritus, Bl. 136. 



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

 tus, Sh., Nat Misc. IX, No. 338, and Gen. Zool. V, part II, pi. lviii, 1, and some 

 neighbouring species. 



N.B. The Ost. areas, Seb. Ill, xxiv, 9, is perhaps a mere variety of the cornuttu ; 

 and the gibbosits, Aldiov. 561, appears to me to be a badly drawn triqueter. 



