TRACHYPTERIDJE. 217 



Genus I. — Trachypterus, Gouan. 



Bogmarus, Bl. Schn. Gymnogaster, Briinnich. 



Definition as in the family, with each ventral well developed if present, but 

 sometimes absent. Caudal fin present, and placed mostly above the longitudinal axis 

 of the body. No air-bladder. Pyloric appendages numerous. 



The ventral fins, as originally remarked, appear to be absent in some specimens, 

 and the genus Gymnogaster was instituted for the reception of such forms. That 

 this fin is mostly present seems to have been proved, but not so among such 

 examples as have been taken along the coasts of Great Britain. Still it is an 

 open question whether its absence may not be the result of age, a mark of sex, 

 or due to some other cause, under which circumstances I have deemed it best to 

 leave names as they are* and await future specimens being obtained for examina- 

 tion. In the very young of the known forms the first few dorsal rays are very 

 prolonged, often considerably longer than the body, while along their edges at 

 irregular distances are short projections on either side : the ventrals likewise 

 are very elongate, and the caudal rays much longer than in adults. 



It is stated by Olafsen that in Iceland these fishes are considered venomous, as 

 ravens do not touch them, but as Mr. Reid observed the lesser black backed gull 

 will eat them at Orkney, this statement appears to be doubtful, more especially as 

 Duguid on the authority of Mr. Strang says, that they are occasionally used as 

 food by the natives of Orkney. Panceri (Rend. Ace. Napol. 1871, April) 

 remarks that the fat of Trachypterus iris is phosphorescent. 



Geographical distribution. — North Atlantic Ocean, especially off the coast of 

 the Orkneys, and the North Sea coast of Scotland to Yorkshire, and the Atlantic 

 coasts of Europe and the Mediterranean. It has also been taken at Valparaiso 

 and the Mauritius. 



1. Trachypterus Arcticus, Plate LXIIL 



Vogmeri or Vaagmar, Olafs. Island Reise. § 684, t. xliii. 



Gymnogaster arcticus, Brunn. Nye Saml. Dansk. Vid. Selsk. Skr. iii, p. 408, 

 t. B, f. 1-3 ; Faber, Fische Isl. p. 66 ; Nilss. Prod. p. 107 ; Walb. Artedi, iii, 

 pi. iii ; Fleming, Mag. Nat. Hist.f iv, 1831, p. 215, c. fig. ; Swainson, Fishes, ii, 

 p. 258. 



Bogmarus islandicus, Bl. Schn. p. 518, t. ci. 



'Gymnetrus arcticus, Cuv. Regne Anim. ; Jenyns, Brit. Vert. p. 372. 



Trachypterus bogmarus, Cuv. and Val. x, p. 346 ; Yarrell, Brit. Fishes (Ed. 1) 

 i, p. 191, c. fig. (Ed. 2) i, p. 210 (Ed. 3) ii, p. 282 ; Duguid, Proc. Zool. Soc. 1851, 

 p. 116; Gaimard, Voy. Isl. et Gronl. Zool. Poiss. pi. xii ; Collett, Norges Fiske, 

 p. 78 ; Winther, Ich. Dan. Mar. p. 24. 



Trachypterus voqmarus, Reinh. Vid. Selsk. Skr. vii, D. p. 65, c. fig. ; Lilljeborg, 

 Ofvers. af. Vet.-Akad. Forh. 1849, p. 33 ; Kroyer, Dan. Fiske, i, p. 292 ; Report 

 Montrose Soc. 1873, p. 4, with a photograph. 



Vogmarus islandicus, Reid, Ann. and Mag. Nat. Hist. (2) iii, 1849, p. 456, 

 pi. xvi. 



Trachypterus arcticus, Nilss. Skand. Fauna Fisk. p. 162 ; Duguid, Proc. Zool. 

 Soc. 1851, p. 116 ; Gunther, Catal. iii, p. 305 ; Collett, Norges Fiske, p. 78, and 

 Christ. Vid. Selsk. Fordh. 1879, No. 1, p. 59. 



Deal-fish, Couch, Fish. Brit. Isles, ii, p. 246, pi. cxviii. 



B. vi, D. 158-165 (172), P. 5 (10-11), V. (6). C. 7-8. 



* While investigating this question I have been to the Newcastle and Montrose Museums, and 

 also to Norwich, where I examined the example captured there in 1879. 



f I must draw particular attention to no ventral fins having been present in the three British, 

 examples which I have seen, namely, at Montrose, Newcastle, and Norwich, and from which my 

 figure was made aud my description taken. 



