862 Bulletin 47, United States National Museum, 



Families of SCOMBROIDEI. 



a. Ventral fins each composed of about 15 soft rays, attached to a very long pubic bone; cora- 

 coid bones very large and heavy; body very deep, compressed, unarmed, covered with 

 minute scales. LAMPRIDID;E, cxxx. 



aa. Ventral fins with less than 8 soft rays, usually I, 5, sometimes wanting. 



b. Bones of snout and upper jaw united and prolonged into a distinct sword; vertebra; 

 about 24; scales minute or rudimentary. 



c. Ventrals of 1 to 3 rays each; teeth present; scales present. ISTIOPHORID/K, cxxn. 

 cc. Ventrals and teeth wanting in the adult; scales obsolete. 



XIPHIID.*:, cxxin. 

 66. Bones of snout not prolonged in a sword. 



d. Body fusiform or band-shaped, with many vertebrae (30 to 120), small or minute 



scales and distinctly forked caudal on a slender peduncle (the fin sometimes 

 wanting); lower jaw well developed, usually with a slit in the flesh to permit 

 its motion; dorsal and anal long, the spinous part of dorsal well developed; the 

 last rays of both fins often developed as finlets. 

 e. Caudal fin present. 



/. Soft dorsal and anal distinct from spinous part, the anterior rays forming a 



more or less distinct lobe. 



g. Body moderately elongate, fusiform; caudal peduncle with a distinct 

 keel; fiulets always present; ventrals I, 5; third and fourth phar- 

 yngeals united. SCOMBRIDJE, cxvin. 



gg. Body decidedly elongate; caudal peduncle without keel; finlets pres- 

 ent or absent; ventrals I, 5, or variously reduced; dentition strong. 



GEMPYLID^E, cxix. 



ff. Soft dorsal and anal more or less continuous with spinous dorsal, their 

 anterior rays not forming a distinct lobe; ventrals rudimentary. 



LEPIDOPID^E, cxx. 



ee. Caudal wanting, the body tapering to a point; ventrals rudimentary or want- 

 ing; dorsal and anal very long and low, continuous; dentition very strong. 



THICHITJRID.E, cxxi. 

 dd. Body and fins various, not showing the combination above noted under d. 



//. Scales, if present, cycloid or ctenoid or lobate, not bony nor parchment-like; 



sometimes, especially in the young, with a median ridge on each one. 

 t. Caudal fin lunate or forked (or if rounded, the dorsal with very weak spines). 

 j. Anal fin not longer than dorsal and more or less similar to it in size 



and form. 

 k. Vertebrae 10 + 12 to 15 = 22 to 25. 



i. First dorsal with its rays connected by membrane, sometimes 



becoming obsolete with age. 



m. Anal preceded by 2 free spines (these often obsolete with 

 age, connected by membranes to the fin in the young) ; 

 no teeth in the oasophagus. 



n. Scales minute or obsolete, cycloid, those along lateral 

 line sometimes armed; tail widely forked; third 

 and fourth pharyngeals separate, 

 o. No free anal spines; dorsal spines long and fila- 

 mentous; pectorals very long and falcate; 

 caudal well forked. NEMATISTIID^E, cxxiv. 

 oo. Dorsal spines not long and filamentous; anal 

 with two free spines, in young. 



CARANGID^:, cxxv. 



wn. Scales moderate, weakly ciliate; tail not deeply forked; 

 canine teeth present. POM ATOM ID;E, cxxvi. 



mm. Anal without free spines; scales moderate; oesophagus 

 with tooth-like processes, dorsal fin very long; cau- 

 dal little 'forked. CENTROLOPHID.S:, cxxxiv. 



