458 PISHES OF THE FIRTH OF FORTH. 



Division. Page. 



! Membranes of the anterior part of tlie dorsal fin 

 terminating in loose filaments 21 

 Membranes of the dorsal fin entire 23 



21. 



Preoperculum entire 22 



! Preopercnlum denticulated Crenilahrus. 259 



f Base of the dorsal fin without spines Labrus. 256 



"" t Base of the dorsal with a series of forked spines. Zeus. 220 



( Teeth in one row only in each jaw Blennmg. 233 



( Teeth in two rows in front of each jaw Murcenoides. 235 



( Ventrals united in the formofaconcave disk... Liparis. 383 



I Ventrals separate Zoarces. 237 



f Dorsal fin situated over the anal fin 26 



25. \ 



I Dorsal situated over the ventrals or nearly so.. 31 



i Mouth placed underneath, without teeth Acipenser. 403 



1 Mouth placed at the extremity, with teeth 27 



r Three or more spines in front of the dorsal fin. Gasterosteus. 190 

 ' i No spines in front of the dorsal fin 28 



28. 



( Caudal fin forked 29 



I Caudal fin not forked Cyclopterus. 380 



(Dorsal fin with finlets Scomberesox. 276 



29 \ 



' ( Dorsal fin without finlets 30 



( Lcnath of doi'sal fin exceeding twice its height. Belone. 274 



30 ^ to to 



(.Length ofthe dorsal about equalling its height. Esox. 272 



( Snout with barbules Cobitis. 270 



31. ' 



^ Snout without barbules 32 



32. 



Tongue rough with minute teeth Clupea. 316 



[ Tongue smooth without teeth 33 



/- Central line of the beUy very rough, strongly 



33.^ serrated Alosa. 329 



'central line of the belly smooth Leuciscus. '^dfi 



(Two dorsal fins 35 



I Three dorsal fins 55 



