FOSSIL FISH. 395 



ichthyolite, as the head is entirely wanting. There remain of 

 the spinal column twenty crowded vertebrae, with strong 

 spinous apophyses. The tail has about fifteen : the abdo- 

 minal cavity is small : the pelvian fins have seven or eight 

 radii. The upper fin is single, occupies almost the entire of 

 the back, and is composed of twenty spinous rays. The anal 

 fin occupies nearly the entire space between the anus and the 

 caudal fin. It has three large spinous rays, and about twelve 

 more smaller. The caudal fin is incomplete. 



Z, platessa, De Blain. Another ichthyolite, in the collec- 

 tion of M. Brogniart, and probably appertaining to this genus. 

 It is a skeleton indicating an oval, elongated fish, somewhat 

 like pleuronectes platessa. The head would appear, though 

 very mutilated, to have been pointed. The vertebral column 

 is composed of twenty-two articulations. The terminal fin is 

 deeply bifurcated : the dorsal has but one spinous ray remain- 

 ing : there is no trace of the anal. Though referred to Glaris, 

 the locality from which this fossil came is unknown. 



Zeus spinosus, De Blain. Another ichthyolite, in posses- 

 sion of M. Brogniart, and apparently of a dilfferent species. 

 The head is almost entirely effaced. The vertebrae seem to 

 have been about twenty. The tail is deeply bifurcated, and 

 has about eight radii in each lobe. There are no traces of 

 pectoral fins. A long spinous ray, in nearly the middle of the 

 belly, may have belonged to a pelvian. The dorsal fin seems 

 to have been divided into two portions : the anal fin is extended 

 to within a small distance of the tail. The determination of 

 this species is hable to doubt ; and the locaUty of the fossil, 

 though arranged with those of Glaris, is not known. It is, how- 

 ever, certain, with respect to the eight species now enumerated, 

 that the formation in which all have been found is marine. 



Nothing of any certainty is determined respecting the ich- 

 thyolites of Mount Pilate ; still M. de Blainville does not think 

 that they have any relation with those of Glaris, because the 

 disposition of the fossil remains seems very different ; because 



