106 



33. Two dorsal fins. 39. 



39. Mouth produced into a tube ; body elevated ; teeth, none ; 



scales none, or small ; body covered with a cuirass or 

 with nonconfluent ossifications. (Cextriscus scolo- 

 PAX.) Centriscid^ — XIX. 

 „ Mouth not produced ; body not elevated. 40. 



40. Spines of the first D. more than four. 40«. 



„ First D. with four stiff spines. Mugilid^e — XVIII. 



40i2. No barbels ; spines of first dorsal feeble, flexible ; teeth 

 minute ; a silvery band along the side. Minute fishes. 

 Atherinid^e — XVII. 



41. Body symmetrical, with an eye on each side of the head. 42. 

 „ Body unsymmetrical ; both eyes on the same side of the 



head, on the upper, which alone is coloured. Pleuro- 

 NECTiD.^ — XXVIII. {Type^ Flounder.) 



42. Ventrals thoracic ; tail tapering to a fine point; no caudal. 



MACRrRiD.ii — XXVI. {Type^ Ling.) 

 ,, Ventrals jugular. 43. 



43. One, two, or three dorsal fins, occupying nearly the whole of 



the back ; one or two A. fins, with or without a Ijarbel ; 

 caudal free, or, if united to D. and A., the dorsal has a 

 separate anterior portion ; V. with several ravs. Gadidje 

 —XXV. (7y;;f, Rock Cod.) 

 „ One dorsal united to caudal ; no separate anterior dorsal or 

 anal. Ophidiid.e — XXVI. {Type^ Ling.) 



44. Second dorsal composed of an adipose fin, without bony 



rays. 45. 

 „ No adipose fin present. 47. 



45. Dorsal fin very elongate, occupying nearly entire length of 



back ; opercular apparatus incomplete ; oviduct present. 

 SCOPELID.12 — XXX. 



„ Dorsal not elongate ; opercular apparatus comi)lete ; no 

 oviduct. 46. 



46. First dorsal before the vent ; margin of upper jaw nearly 



altogether formed b}' maxillary ; body naked, or scaly ; 

 ]iyloric ai)pendages, none ; minute fishes. Haplochi- 

 TOXiD.^ — XXIX. {Type^ Freshwater Herring.) 

 „ First dorsal over the A'ent in minute species, before the vent 

 in the larger introduced species; body covered with scales; 

 margin of upper jaw formed by the intermaxillaries 

 laterally ; pyloric appendages generally numerous. Sal- 

 JIOXID.13 — XXXI. {Types^ Salmon ; Smelt.) 



47. Body apparently scaleless. 48. 

 „ Body with scales. 49. 



48. Dorsal short ; belly rounded ; vertical fins not continuous 



with caudal ; in creeks, fresh or brackish. Galaxid^ 

 —XXXII. {Type, Jolly tail.) 

 „ Dorsal and anal long and continuous with caudal ; body 

 rounded or band-shaped ; under lens the scales become 

 apparent ; no ventrals. MuR.F.xiDiE — XXXVIII. {Type^ 

 Freshwater Eel.) 



