412 SYNOPSIS. 



in each jaw; two dorsal fins, the first consisting of spines 



only. 



Sp. 213. B. capriscus. European File-fish. First dorsal a 

 little before the middle of the body, composed of three 

 strong spines connected by a membrane, the first spine 

 much longer than the other two ; second dorsal long, and 

 reaching nearly to the caudal ; anal corresponding ; ante- 

 rior part of the abdomen with a strong bony keel : colour 

 brownish-grey, occasionally tinted here and therewith blue 

 and red. Cuv. Reg. An.; Yarr. Brit. Fish., ii. 472. 



SECOND SERIES. CHONDROPTERYGIAN, OR 

 CARTILAGINOUS FISHES. 



FIRST DIVISION. CARTILAGINOUS FISHES WITH 

 FREE GILLS. 



FAM. XXVI. Sturionidce. Fain, of Sturgeons. Upper jaw 

 formed by the palatine lone, firmly united to the maaillary; in- 

 termaxillary rudimentary; branchice free, with one large exter- 

 nal aperture; body covered with large osseous plates. 



GEN. CHI. ACIPENSER. Body elongated and angular, the 

 plates arranged in longitudinal rows ; mouth placed beneath, 

 small, protractile, without teeth ; snout with four barbules be- 

 neath. 



Sp. 214. A.slivrio. Common or Sharp-nosed Sturgeon. Os- 

 seous tubercles in five longitudinal rows, the pointed cen- 

 tral spines directed backwards ; nose long and pointed : 

 eyes small ; operculum covered with striae radiating from 

 a centre ; dorsal single, placed near the tail ; caudal 

 forked, the upper lobe much longer than the under ; co- 

 lour, various shades of brown ; tubercles white in the 

 centre ; under side silvery. Linn., Perm. Brit. Zoo/., iii. 

 p. 164, pi. 22 j Don. Brit. FisJi., pi. 65 ; Yarr. Brit. Fish., 

 ii. p. 475. 



