136 



Cycloid Acastiioptekes.- 



-FISHES.- 



-ECOJIIiKIDKS. 



The genera are — Thi/rsUes; Gempijlus; Lcpidojms; Trtchi- 

 tirus; Epinnula (Pney) ; Dicrotus (Guiither) ; .l^Aanp/Jus (Lowe) ; 

 :ciiJ RuvcUus (Valeuc). 



The Scabbard-fish {Lqnilnpus art/i/reus) has been 

 taken on the Dovoushiro coast, and is tlie only British 

 member of tlie family. Young ones not more tlian 

 ten inches in length have been seen, but the old fish 

 exceeds five feet. One of the latter was in the act of 

 swimming in Salcombo harbour with amazing velocit}', 

 with its liead raised out of the water, when it was 

 killed by a blow from a fisherman's oar. RuvcUus prc- 

 tiosus of Cocco is studded with bony spines on the body. 



Family XXIX.— SCOMBRIDES (Scomhridw). 

 Plate 10, figs. 51, 52. 



The Scoraberoid or Mackerel aspect of this family is 

 easily recognizable, proving the assemblage to be a 

 natural one. The Tunnies, which are its most active 

 and powerful members, have bone-corpuscles in their 

 skeletons, and thus form a transition to the Fliysos- 

 tomcs, whose bony framework is generally built up of 

 true bone, and not merely of osteoid structure, like 

 those of the Tdeostomi, or Acanthopteros in general. 



The texture of the bones of the Scombrides is for 

 tlie most part loosely fibrous, penetrated by an oily 

 secretion, but with a small quantity of earthy matter 

 compared to their extent of surface. This gives great 

 Tghtness to the skeleton, and accords with the habits 

 ^>[ the mackerel tribe, which live on the surface of the 

 ocean, and delight in skipping into the air, such motions 

 being effected by their strong caudal muscles, coloured 

 in part with red blood. The tail at the setting on of 

 the caudal fin, is much more slender than in other 

 fishes, but tapers gradually from the fusiform or com- 

 pressed body ; and the crescentic or swallow-tailed 

 manner in which the fin expands, gives it much power 

 as a propeller. In many species the sides of the tail 

 are keeled, and they are also frequently protected by a 

 ridge of scutiform pointed plates. 



The scales are in this family generally small, tender, 

 and smooth ; sometimes lost in a shining nacry surface, 

 as in the common mackerel. 



In most Scombrides the jointed portion of the dorsal 

 fin is separated from the spines by a notch, or by a 

 naked space, and the membranes are generally delicate, 

 disappearing partially with age. Sometimes the spines 

 of the dorsal stand singly, each with a small triangular 

 membrane behind it, or without a membrane at all ; 

 ami not unfrequcntly the posterior tufted rays of the 

 soft dorsal and anal are similarly isolated, in which 

 case they receive the appellation of" pinnules " (fmisscs 

 pinnules of Cuvior). In the majority of the genera, at 

 least two of the anal spines are detached in front of 

 that fin. Most generally the vcntrals are situated 

 nnder the pectorals, but in some rare instances they 

 are absent. Some species have a short oblique cuta- 

 neous crest on the base of each side of each lobe of the 

 caudal fin. No armature exists on the opercular 

 pieces of these fishes. The branchiostegals commonly 

 number seven ; sometimes, however, there are no more 

 than six, and in other instances they amount to eight. 



In the structure of the jaws, tlie Scombrides resemble 



the other Acanthopteros, in having the upper lip bor- 

 dered wholly by the generally dentiferous premaxil- 

 laries. The edentulous maxillarics lie in the membrane 

 behind, and approach the corner of the mouth only 

 wlien the jaws are widely extended. They are not 

 serrated ; and a similar smoothness and absence of 

 projecting angular points prevails in the heads of 

 these fishes, which have very generally the form of 

 compressed cones, adapted to swift motion through 

 the water. 



The numerous pancreatic CEcca are often so conjoincil 

 as to form a tolerably compact glandular mass. Most 

 of the Scombrides have a larger and more complicated 

 brain than the generality of fishes. The stomach is 

 large and co:?cal, with folds of the internal membrane 

 that greatly extend the surface. Some species have 

 an air-bladder; others, even in the same genus, want 

 that organ. 



All these characters cannot be found in every 

 member of the family, being variously combined in 

 varying numbers in the diflerent groups. The fanjily 

 as here restricted is less extensive, but more natural 

 than it was as propounded by Cuvier, having been 

 made so by the separation of some of his sections of 

 genera. 



The genera arc — Scomhcr; TJiyniws; Aitxis; Pclnni^s, 

 Cyhlum; Naucratcs; Elccate; Jh/psiptefa ; Tracliurus ; Caran- 

 f/ichlhijs; Caranx ; * Airif/rctosus ; Microptcrt/x (Agassiz); 

 Scriola (Cuv.); SeriolcHa (Guichenot); SerioUchthys (Jihckn'); 

 Naucknis; Porlhmens ; Cliorinemus; Lichla; Tannodon; Tra- 

 chinntus; Paltnunis (Viiik:\y or Pamme/Hs, Giinther) ; Paropsis 

 (Jenyns); OUstes; Scyrls; Lncfarius; Pscnes; No?tieus ; 0"S- 

 terochixma (Kichnrdson ); Cubiceps (Lowe); NyHomcnus 

 (Guntlicr); Platystethus (id.) 



The British species are — the Mackerel [Scomhcr 

 scomhrus) ; the Spanish Mackerel [Sc. colitis) ; the 

 Dotted Mackerel [Sc. punctatus) ; the Tunny {Thynmts 

 riiirjaris) ; the Bonito [Th. ptdaniis) ; the Belted 

 Bonito {Th. hracliyplcrus) ; the Gcrmon [Tli. ala- 

 lonrja) ; the Plain Bonito {Auxis vulgaris) ; the Pilot- 

 fish (Naucrates ductor) ; the Derbio [Lichia ylaucus] ; 

 and the Scad (Trcichzinis vulgaris). 



The Scombrides are objects of fisheries, in the Medi- 

 terranean and other seas, as extensive and important to 

 the maritime populations there as the herring fisheries 

 are in the north. The Tunny is one of the largest of 

 marine fishes, since it attains the weight of one thou ■ 

 sand poimds or more ; when under three hundred 

 pounds, it is termed by the Sards mczzo-tonno or "half- 

 tunny." Aristotle mentions one that weighed twelve 

 hundredweight. The abundance of these fishes in 

 the Bosphonis, is said to have been the origin of the 

 name of Golden Iloni applied to the port of Byzan- 

 tium. The Tunny fishery was established in a very 

 early age by the Phcenioians on the coasts of Spain, 

 both on the Mediterranean and Atlantic sides of the 

 peninsula, and the fish is represented on the medals of 

 Cai-teja and Tartessus. 



The Tunny fishery of Sicily has been described in 

 a spirited manner by Brydone and Dumas, to whose 



* Mcgalnspis, Decnpterus, Sclar^ Caranf/ioitkst Lcioglossus^ 

 Z^rnspis SelarouJcs^ Lcptaspis^ and Gnathonodon, are dismcni- 

 biTmouts of Caranx, which are not adopted in the catalot^iieg 

 of the British Museum by Dr. Glinther. 



