Fishes of the Western North Atlantic 1 7 



4 b. Point of origin of pectoral fins at least no higher than upper end 

 of gill openings, and usually much lower; at least most of fin rays 

 branched. 



5 a. Upper edge of mouth formed by the maxillary bones as well 

 as by the premaxillaries. Isospondyli, Part 3, p. 89, 



and Part 4. 



5 b. Upper edge of mouth formed by the premaxillary bones 



alone. Iniomi, Part 5. 



I b. No distinct rayed caudal fin; extreme tip of tail either like a whiplash or narrow 



band; its membrane, if any, without rays. Lyomeri, Part 5. 



