296 



ICHTHYOLOGY. 



Classifica- 

 tion — 



Acanthop- 

 terous 

 Fishes. 



standing on the summit of a neighbouring rock, gives 

 warning by signal when he sees a fish approach. The 

 fishermen then row towards it ; and, being so skilful as 

 frequently to strike the fish from a great distance, they 

 throw a harpoon into it attached to a long line. An ardu- 

 ous struggle then commences, during ivhich the aggres- 

 sors are sometimes pulled about by the fish for many hours 

 before they can get it into the boat. The sword-like pro- 

 longation of the snout in Xiphias is formed of the conflu- 

 ent premaxillaries, firmly and immoveably articulated with 

 the prenasal and maxillary bones as in the Scomheresox. 



Family XVT.— SCOMBERID.E. 



Fig. lis. 

 Histiophortut pulchfllus- 



We cannot give more space to the more remarkable forms 

 of this large and important family of fishes. The pecu- 

 harities of their structure, such as tlie loose texture ot their 

 bones, the glandular-like assemblages of pancreatic caeca 

 which they possess, and the papery-like scales, scarcely to 

 be distinguished from the smooth skin, with the neat taper- 

 ing tail and large crescentic caudal, together with the deli- 

 cacy of the cutaneous ibid or membrane, in which the other 

 two vertical fins are developed, and which, from its early 

 disappearance, leaves many of the rays detached in form ot 

 finlets, are all prominent characters of the more typical 

 species, and give such an unity of aspect to the whole 

 group, that it miglit rank as an order, and not as a mere 

 iamily division. The family is generally distributed in all 

 districts of the ocean, and the Temiiodoii saltator is espe- 

 cially a cosmopolitan fish, being foiuid in all the temperate 

 and warmer districts of the Atlantic and Pacific Oceans. 

 In concluding, we must express our regret that M. Valen- 

 ciennes should have adopted the word Rhombus, first used 

 by Lacepede to distinguish a Scomberoid genus, but which 

 has been generally employed by ichthyologists to designate 

 the Turbots among the Pleuronectida. Cuvier iiad given 

 the Scomberoid genus the name of Peprilus in the second 

 edition of the Reyne Animal, and this being also a Lace- 

 pedian name of this genus, the continuance of it would have 



Fig. in. 

 Gasterochisma iiwlampus. 



avoided the mistakes that are likely to arise from two very 

 different genera retaining the same appellation. 



Classifica- 

 tion — 



Scales generally small, tender, smooth, seldom extending to the , 

 vertical fins ; bones less solid than in most other osseous fishes. "' 



The tail and caudal fin, generally, very vigorous. Pancreatic Cieca 

 numerous, and frequently united in bunches. Xo armature on the 

 opercular pieces. In many, the sides of the tail are keeled and 

 armed with keeled, often acute scales. The posterior rays of the 

 second dorsal and anal are often detached from the rest of the fin. 

 Sometimes the spines of the fir.st dorsal are not connected by mem- 

 brane. The front anal spines are detached in most; the caudal is 

 very frequently large. These characters are variously combined, 

 none being common to all, but they serve to divide this numerous 

 family into tribes. 



Tkibe I. — Finlets, and no Armature on the Lateral Line. 



First dorsal continuous, the rays of the second detached, forming 

 finlets. Body fusiform. Caudal large and vigorous. Tail becom- 

 ing very slender, and more or less keeled. In some there is an 

 interval between the first and second dorsal, in others these fins 

 are contiguous ; in some the scales of the tliorax are large, forming 

 a corselet. Most, or all, have seven branchiostegals. 



Gexis I. Scomber, Linn. Detached finlets behind the dorsal 

 and anal ; a large interval between the dorsals. Tail with a slight 

 ridge on each side, but no acute keel. Generally an air-bladder, 

 though in some species that organ is absent. Fourteen species. 



Gexus 11. TiiVNXOS, Cuv. JIackerels, but with contiguous 

 dorsals ; the scales of the thorax larger and stronger, forming a 

 corselet which ends posteriorly in points. Detached finlets more 

 numerous; no free spine in front of the dorsal. .An acute carti- 

 laginous projection on the lateral caudal ridge. Thirteen species. 



Genus III. Aiixis, Cuv. Dorsals separated by an interval. 

 Tail keeled on the sides ; intermediate between, and connecting the 

 Jlackerels, having widely separated dorsals, to the Tunnies and 15o- 

 nitos, with small teeth, numerous finlets, keeled tail, and contigu- 

 ous dorsals. Three species. 



Genus IV. Pelamys, Cuv. Differs from Auxis in having 

 contiguous dorsals and strong pointed teeth, standing ratherwidely. 

 Two species. 



Genus V. Cyeicm, Cuv. No corselet. Compressed lancet- 

 pointed trenchant teeth. Detached finlets and long first dorsal of 

 Thynnus. Elongated body, keeled tail, and no pectoral cuirass; 

 this last character distinguishing them from Pelamys. Very short 

 villiform teeth on the chevron of the vomer, palatines, tongue, and 

 branchial arclies. .Sixteen species. 



Genus VI. Tuyusites, Cuv. No lateral caudal keel; no pectoral 

 corselet. First dorsal contiguous to the second. Body elongated, 

 much compressed. Small but perfect ventrals. Teeth pointed, 

 compressed, trenchant ; longer and stronger anterior premaxillary 

 teeth ; palatine teeth small, pointed. Four species. 



Genus Vll. Gempylus, Cuv. yAursifcs with rudimentary ven- 

 trals. No palatine teeth. Two species. 



Gends VIII. Rovettus, Bonap. (Ruvetus, Cocco; Tetragonurus, 

 Lowe ; Aplurus. Idem.) Body elongated, compressed. Head covered 

 with a scabrous leathery skin. Belly keeled on the ventral edge. 

 Tail compressed, without a lateral keel. Head unarmed; snout much 

 abbreviated. Gill-openings very wide. Mandible shorter than 

 the premaxillaries. A row of equidistant, compressed, slightly 

 recurved, serrated teeth on the jaws; some of them long, especially 

 the premaxillary ones near the symphysis, which are the longest ; 

 a uniserial range of smaller ones on the vomer and palatines. Two 

 dorsals, with finlets above and below the tail. Caudal forked. 

 Branchiostegals seven. Many pancreatic caeca ; small air-bladder. 

 One species. 



Appendix to Tribe I. 



Genus IX. Lepidopus, Cuv. (Aphanojms, Lowe.) Form of 

 Gemjyylus and Tkyrsites, even more elongated ; but they have no 

 soft dorsal or finlets, the spinous rays running all along the back. 

 Vestiges of ventrals in form of a little squamoid appendage, with 

 the styloid pubic bone felt through the skin. Teeth like those 

 of Tkyrsites on the jaws ; none on the vomer, and very fine ones 

 on the palatines. Branchiostegals six. A long ca'cal stomach ; 

 twenty-three pancreatic caica ; air-bladder long and narrow. One 

 species. 



Genus X. Trichiurus, Linn. Head, body, and dentition of 

 Lepidopus. but without a vestige of ventrals. The dorsal, also, 

 is spinous throughout like that of Lepidopus ; while the anal con- 

 sists of a series of spines that scarcely protrude through the skin, 

 and the tail ends in a filiform point without a caudal fin. Four 

 species. y^ ^•^■j'A^. f 



Genus XI. Ne.michtiiys, Rich. (Voy. of the Sk^tAwvpI- x., 

 1848.) Form greatly elongated, and tapering posteriorly into an 

 exceedingly long filamentous-looking tail. Head longer than the 



terous 

 Fishes. 



