COMPENDIUM OF GENERIC DISTINCTIONS. 



019 



Family. CEPOLID.E. — Body very long and compressed; 



scales small and cycloid. Dorsal and anal very long, with soft 

 rays. Ventrals under thorax, one spine and five rays. Bran- 

 chiostegals six. 



Genus. Ckpoi.a. — As family. Many temperate seas. 



Family. CENTRISCID.E.— Body deep, compressed, and bones 

 of month produced into a long snout. Body shielded or 

 cuirassed. Two dorsals, spinous, short, and with a single strong 

 spine; ventrals small and on abdomen. Few vertebrae. 



Genus. CentriSCCS. — Body with scales or prickles. Many 

 seas. 



Family. FISTULARIDJE.— Body much elongated; bones of 

 head produced into a long tube, ending in a small^mouth. Body 

 shielded. Ventrals on abdomen, with six rays; no spine. 

 Branchiostegals five. Many vertebrae. 



Genus. Fistularia. — Body not sealed. Tropical seas. 



Family. MASTACEMBELID-ffi:.— Body long and eel-like, very- 

 small scales. Jaws very long, slightly moveable. No ventrals. 

 Gill-opening only a small slit under side of head. Branchios- 

 tegals six. 



Genus. Mastacambelus. — Appendage of snout not striated 

 below. Fresh waters of East Indies. 



Order. MALACOPTERYGI I.— Rays of the fins jointed, and 

 mostly divided at the point. 



Sub-order. SUB-BRACHII. — Ventral fins placed under or 

 in front of pectorals. 



Family. PLEURONECTID.S:.— Body very much compressed 

 and sealed. Both eyes on same side of head. Pectorals some- 

 times wanting. 



Genus. Soi.ka. — Jaws hidden under skin; teeth in several 

 rows, on lower side only, cylindrical and minute. Many seas. 



Genus. MonoCHIRUS. — Pectoral wanting on lower side. Tem- 

 perate seas. 



Genus. Achirus. — Pectorals wanting. Temperate seas. 



Genus. Pleurokectes. — Jaws apparent, not scaled. Tail-fin 

 distinct. Temperate seas. 



Genus. Peatessa. — Teeth in single row. Dorsal fin com- 

 mencing over upper eye. Temperate seas. 



Genus. HlPPOGLOSSUS. — Teeth sharp, long, and curved. Body 

 rather narrow. Temperate seas. 



Family. GADIDJ2. — Body long and scaled. Head sym- 

 metrical. 



Genus. Gadus. — Head smooth. Teeth conical, in intermax- 

 illaries, vomer, and lower jaw. Three dorsals. Brf.nchioste- 

 gals seven. Ventrals under throat and pointed. A barbule on 

 the chin. Colder seas. (Including Morrhua. I 



Genus. Merlangus. — As Gadus, but no barbule. Many seas. 



Genus. MERLUCIUS. — Two dorsals, one long anal. No barbule. 



Sub-order. APODES. — No ventrals. Body long and snake- 

 like; skin thick and soft; often with minute scales hidden in 

 skin. 



Family. OPHIDINI. — Swimming-bladder either closed or 

 wanting. 



Genus. Ammodytes. — Body long, with minute scales. Lower 

 jaw longer than upper. Teeth none. Branchiostegals seven. 

 Dorsal and anal very long, tail-fin forked. Many seas. 



Family. ANGUILLIDJE. —Teeth comb-like. Gill-openings 

 on sides. Pectoral fins conspicuous, dorsal and anal running 

 round tail. 



Genus. Anguti.t.a. — Head and tail blunted. Seas and rivers. 



Family. CONGERIDiE. — Dorsal commencing close to head; 

 skin without scales. 



Genus. Conger. — Front nostrils in short tubes atend of snout. 

 Teeth of palate and vomer in straight, chisel-shaped rows. Many 

 seas. 



Family. MTTRiENIDJE. — No pectorals; gill-openings only 

 narrow slits. 



Genus. Mur.ena. — Single row of teetli on nasal hone. Many 

 seas. 



Family. GYMNOTID^.— No dorsal; anal very long. 



Genus. Gymnotcs. — Scales none. 



Family. LEPTOCEPHALID.E:.— Small, scaleless, very much 

 compressed, and transparent. Lateral line formed by intersec- 

 tion of muscles. Many seas. 



Genus. Hyophori's. — Jaws long, straight; body deep behind 

 head. Tail pointed. 



Genus. Tilurus. — Membranous dorsal beginning at head. 

 Anal none. Pointed teeth in both jaws. Tail very long. 



Genus. Leptocephalus. — Muscular bands bent regularly 

 forward. Tail moderate. 



Sidi-order. ABDOMINALES — Ventrals on abdomen and 

 behind pectorals, sometimes absent. Swimming-bladder in 

 most, and with an air-duct. 



Family. HETEROPYGIDJE.— A'entrals small. Dorsal set far 

 back. Gill-apertures small. Body scaled. Teeth small and 

 sharp in palate, none on vomer or tongue. Branchiostegals seven. 

 Eyes none external. 



Genus. Amislyopsis. — As family. North America. 



Family. CLUPEID./E.— Fatty dorsal wanting. Body with dis- 

 tinct and mostly large scales. Two inferior pharyngeal bones. 



Genus. Exgraulis. — Head pointed, upper jaw longest, gape 

 very deep. Ventrals before dorsal. Branchiostegals twelve. 

 Many seas. 



Genus. Clupea. — Body compressed, scales loose and large. 

 Teeth minute or wanting. One dorsal. Abdomen keeled. 

 Many seas. 



Family. ES0CID.2E.— Dorsal fin set far back, near tail-tin. 

 Edge of upper jaw partly formed by intermaxillary bone. 



Genus. Exoccetus. — Pectorals large and very long, used for 

 flight. Lower lobe of tail-tin elongated. No teeth on palate. 

 Warm seas. 



Genus. HeMIRAMPHUS. — Lower jaw long and projecting. 

 Teeth small and placed in a belt round each jaw, none on pal- 

 ate. Body much elongated. Pacific. 



Genus. Bej.oxe-. — Both jaws much lengthened and slender, 

 lower longer than upper. Teeth small in both jaws, of unequal 

 sizes. Many seas. 



Genus. Esox. — Body rather long; snout flattened. Mouth, 

 jaws, and palate, crowded with sharp teeth. Fresh waters. 



Family. SALMONID.ffi.— Second dorsal of a fatty consistence, 

 without rays. 



Genus. Salmo. — Head smooth. Teeth on vomer; palatine 

 and maxillary bones. Branchiostegals often unequal on the two 

 sides. Seas and fresh waters. 



Genus. Scopelus. — Teeth sharp and conical in both jaws. 

 Branchiostegals nine. Palatine teeth very small. Many seas. 



Genus. Serrasalmur. — Teeth in both jaws, triangular, flat, 

 sharp-edged, mostly in a single line. Body rather compressed. 

 Abdominal line serrated. Rivers of South America. 



Family. CYPRINIDONTIDiE.— Jaw-teeth very small. Throat 

 crowded with teeth. Branchiostegals five — six. Whole of head 

 scaled. No fatty fin. 



