ARTIFICIAL KEY. 31 



A. Dorsal fin very short; body mailed Agohid^, 74. 



hh. Dorsal fin very long; body with small scales. 

 i. Dorsal and anal joined to the caudal. 

 ./. Gill membranes free from the isthmus ; ventrals very slender, 



barbel-like Ophidiid^, 87. 



jj. Gill membranes united to the isthmus. . . Lycodid^, 86. 

 a. Dorsal and anal free from caudal ; tail isocercal. Gadid*, 88. 

 CC. Body scaleless, smooth or more or less prickly or warty, 

 i. Breast with a suckijig-disk. 



I. Gill membranes frea from isthmus ; no spinous dorsal. 



GOBIESOCID^, 80- 



II. Gill membranes attached to the isthmus. 



m. Skin smooth Lipaeidid^:, 77. 



mm. Skin warty Cycloptekid.5E, 78. 



Tele. Breast without sucking-disk. 



n. Ventrals completely united Gobiid^, 82. 



nn. Ventrals separate. 

 0. Ventral rays I, 5. 

 p. Dorsal and anal with finlets. . . . Scomekid^e, 55. 

 pp. Dorsal and anal without finlets ; two free anal spines. 



Carangid^, 56. 

 00. Ventral rays less than I, 5. 

 q. Upper jaw prolonged into a sword. Istiophokid^, 53. 

 qq. Upper jaw not prolonged into a sword. 

 r. Suborbital with a bony stay. . . . Cottid^i:, 73. 

 rr. Suborbital without bony staj'. 

 s. Dorsal spines two or three ; teeth strong. 



Batrachid^, 79. 

 ss. Dorsal spines 4 to 6; teeth small. 



Gasteeosteid^, 45. 

 sss. Dorsal spines numerous ; teeth comb-like. 



BLENSIIDiE, 83. 



BB. Gill openings small, behind the pectoral fins, which are pediculate. 

 t. Gill openings in or behind lower axil of pectorals ; mouth large, 

 terminal. 

 M. Pseudobranchias present; head broad, depressed; mouth very 



large, with large unequal teeth Lophiid.e, 96. 



uu. Pseudobranchise none ; head compressed ; teeth small. 



AntennakiiDjE, 95. 



tt. Gill openings in or behind upper axil of pectorals ; mouth small, 



below a projecting snout Malthid-e, 94. 



Series III. Ventral Fins entirely wanting. 



A. Gill membranes joined to the isthmus, so that the gill openings of the two 

 sides are not connected. 

 B. Dorsal fin single, of spines only (these sometimes slender, like soft rays). 



C. Molar teeth present Anarrhiohadid.e, 85. 



CC. Molar teeth none. 

 D. Mouth vertical ; body naked. . . . Ckyptacanthodid.e, 84. 

 i)Z). Mouth not vertical ; body scaly Blenniid-e, 83. 



