68 FAMILIES AND GENERA. 



Eyes left. 



Arnoglossiis, mouth small, scales spiny along hinder edge of upper 

 side, 156. 



Zeugopterns, mouth large, vomer toothless, dorsal and ventrals 

 long, 153, 154. 



Lepidorhombus, mouth large, teeth on vomer, scales large and 

 spiny, lateral line not semi-circular over pectoral, 155. 



Rhombus, mouth large, teeth on vomer, scales absent or small, 

 I5 1 - 152. 



Ralidae. (BATOIDEI.) Plates xxxi. and xxxii. 

 Raia, 238-247. 



Salmonidse. (PHYSOSTOMI.) Plates xxv., xxvi,, xxvii. 

 Body ridged. 



Argentina, no teeth on jaws, maxillary short, scales large, 219. 

 Body not ridged. 



Thymallus, dorsal rays over 18, 218. 



Coregonus, dorsal rays under 18, maxillary short, 214 to 217. 



Osmerus, dorsal rays n, maxillary long, 213. 



Salmo, dorsal rays 12 to 15, maxillary long, scales small, 195-212. 



Seisenidae. (ACANTHOPTERYGII.) Plate iii. 

 Scicena, 20. 



SeombresOCidSB. (ACANTHOPTERYGII.) Plate xi 



Exoccetus, pectorals elongated into organs of flight, 89, 90. 



Scombresox, pectorals normal, jaws prolonged into a slender bea!:, 

 finlets present, 88. 



Belone, pectorals normal, jaws prolonged into a slender beak, 

 finlets absent, 87. 



ScombPidSB. (ACANTHOPTERYGII.) Plates vi. and vii. 

 Without finlets. 



Echeneis, first dorsal modified into an adhesive disk, 44. 

 With finlets. 



Scomber, keel on tail represented by two slight ridges, dorsals 

 wide apart, 36 to 38. 



Auxis, keel on tail, dorsals wide apart, 43. 



Pelamys, keel on tail, dorsals close, first dorsal over 20, 42. 



Thynnus, keel on tail, dorsals close, first dorsal under 20, 7 

 finlets, 41. 



Orcynus, keel on tail, dorsals close, first dorsal under 20, 8 or 9 

 finlets, 39, 40. 



