100 ACANTHOPTERYGII. 



Genu's III. — Thynnus (Cuvier), Liitken. 



Thynnichthys, Giglioli. 



Branchiostegals seven : pseudobranchiai present. Body oblong and somewhat 

 compressed. Cleft of mouth deep. Small teeth on the jaws and palatine bones, but 

 none on the vomer. Two dorsal fins with a very short space between them, the 

 spines of the first weak : finlets behind the second dorsal and anal. Scales small, 

 forming a corselet in the anterior portion of the body, but scaleless posteriorly. 

 Lateral line unarmed : a longitudinal keel along either side of the free portion of the 

 tail. Air-bladder, when present, simple. Pyloric appendages numerous. 



This genus' is composed of the smaller tunnies, which differ from the larger 

 forms, Orcynus, in the vomer being toothless, and their having no scales outside 

 the corselet : while irrespective of this, they possess a special development in the 

 form of a net, or trellis, of a portion of the abdominal part of the vertebral 

 column, between the vertebrae properly so-called, and the hsemapophyses, as has 

 been described by Cuvier. 



Although only one species of this genus, viz., Thynnus pelamys, has been 

 recorded from the British seas, it is by no means improbable that others, as 

 T. thunnina, may likewise be occasional visitors, for it has been captured more 

 than once off Denmark, which locality it could scarcely have reached without 

 passing our shores. 



Geographical distribution. — From the seas of Northern Europe throughout those 

 of temperate and tropical regions. 



Thynnus pelamys, Plate XXXVII. 



Renard, i, 20, 113 ; Osbeck, Reise, p. 87 ; Leguat, Yoy. p. 21, c. fig. ; Funnel, 

 Voy. Dampier, p. 158, f . 32 ; Dutertre, Hist. Antilles, ii, p. 214, p. 295, c. fig. 

 Variletta, Humbolt, Obs. Zool. ii, p. 190. Thunnus, Jonston, De Pise. lib. i, tit. i, 

 c. 2, Art. p. 12, t. iii, f. 2. 



Scomber pelaviis, Linn. Syst. Nat. i, p. 492 ; Bl. Schn. p. 23 ; Bonnaterre, 

 Enc. Ich. p. 139 ; Gmel. Linn. p. 1330 ; Bennett, Whaling Voyage, ii, p. 281 ; 

 De la Roche, Ann. Mus. xiii, p. 315 ; Shaw, Zool. iv, p. 588 ; Scouler, Mag. Nat. 

 Hist, vi, 1833, p. 529 ; ? Risso, Ich. Nice, p. 167 ; Thompson, Proc. Zool. Soc. 

 1835, p. 80 ; Jenyns, Manual Brit. Vert. p. 363. 



Scomber pelamides, Lacep. iii, p. 14, ii, pi. xx, f. 2. 



Thynnus pelamys, Cuv. and Val. viii, p. 113, pi. ccxiv; Temm. and Schleg. 

 Fauna Japon. Poiss. p. 96, pi. xlix ; Rich. Ich. China, p. 267 ; Cuv. Regne Anim. 

 111. Poiss. pi. xlvii, f. 2 ; Bleeker, Amboina, pi. 41 ; Yarrell, Brit. Fish. (Ed. 2) 

 i, p. 157, c. fig. (Ed. 3) ii, p. 215 ; Parnell, Fish. Firth of Forth, p. 53 ; White, 

 Catal. Brit. Fish. p. 31 ; Thompson, Nat. Hist. Ireland, iv, p. 94 ; Gunther, Catal. 

 ii, p. 364 ; Steind. Ich. Span. u. Port. 1868, p. 7 ; A. Malm, G3fv. Ak. Fork. 1875, 

 No. 7 ; Poey, Ann. Soc. Esp. 1875, iv, p. 145 ; Day, Fishes of India, pt. ii, 1875, 

 p. 252 ; Mcintosh, Fish. St. Andrew's, p. 173; Winther, Prod. Ich. Dan. Mar. 

 1879, p. 14; Moreau, Hist. Nat. Poissons de la France, 1881, ii, p. 419. 



Thynnus vagans, Lesson, Voy. Coq. Zool ii, p. 162, pi. xxxii. 



Bonito, Couch, Fish. Brit. Isles, ii, p.. 97, pi. lxxxiii. 



B. vii, D. 13-15/^^3- + VIII, P. 27, V. 1/5, A. - l \ + YU, C. 35. 



Length of head 2>\ to 4, of pectoral fin 6 to 8, height of body 3^ to 4 in the 

 total length. Eye — diameter 5 to 6 in the length of the head, If diameters from 

 the end of the snout, and also apart. The posterior margin of the preopercle is 

 3/5 the length of its lower limb. Snout pointed: the lower jaw the longer: the 

 posterior extremity of the maxilla reaches to beneath the middle of the eye. 

 Teeth — in a single row in the jaws, present on the palatines but absent from 

 the vomer. Fins — dorsal spines of moderate strength, the first being strong, 

 two-thirds the height of the body, and nearly twice as high as the rays of the 



