194 PISCES. 



bones are met with in the anal fins, where the foremost of these in- 

 ferior interspines are frequently of remarkable length and strength, 

 as in Pleuronectes. The last vertebrae, or those which abut against 

 the caudal fin, are usually formed in a peculiar manner, being very 

 strongly compressed laterally, and their superior and inferior spines 

 forming large flat bones. Frequently, as in the Anguilliform Fishes, 

 the last vertebrae become smaller in size, but exhibit no peculiar con- 

 formation from the absence of the caudal fin. 



Most of the Osseous Fishes are furnished with Ribs, which vary 

 greatly in number, and are attached partly by their upper and 

 strongest extremity to the transverse processes, and partly to the 

 bodies of the vertebral series, inclining chiefly in the direction for- 

 ward. The ribs are never, as in Man and the higher Vertebrata, 

 laterally compressed, but from before backward, or they are rounded, 

 and frequently present the appearance of slender spiculse. In many 

 fishes, e. g. Balistes, the ribs are small and few in number ; in others 

 they are rudimentary or entirely wanting, as in Lophius, in the Pec- 

 tognathi, and others. 



In many Fishes we meet with a series of bones that have been 

 falsely termed accessory ribs ; they consist of lateral spines, which 

 are attached to the vertebrae above the true ribs, and are plunged 

 amonsf the muscular fasciculi to which they properly belong. They 

 are greatly developed in the Herring, where they stand in two 

 rows. 



It is only in a few Fishes that parts are found which admit of being 

 very remotely compared to a Sternum. To these belongs the chain of 

 little bones, parts of the dermo-skeleton, that in Zeus and Clupea 

 extend from the girdle of the thoracic fins to the anal fin. In other 

 Fishes, e. g. Balistes, a single long bone occupies their place. No 

 costal cartilages are, however, found connecting the ribs with the parts 

 just described, so that the latter can only be viewed improperly as a 

 sternum. 



The Thoracic and Ventral fins of the Osseous Fishes correspond in 

 position to the anterior and posterior extremities, and attempts have 

 been made to reduce the osseous structures which serve for their 

 support to corresponding bones in the arm and foot of the higher 

 Vertebrata. 



As regards the Anterior Extremities, they appear to be completely 

 wanting in probably none of the Osseous Fishes. As in many 

 Serpents and Apodal Lizards, even where they are not indicated ex- 

 ternally by fins, they still exist, of which examples are met with in 



