4S4 



SCANDINAVIAN FISHES. 



Ill tlie fii'st relation, the length of the snout in 

 |)roportion to the postorbit;il length of the liead, the 

 direction of development difters in the two forms, and 

 thus indicates a true specitic distinction. In the other 

 i-elations the direction of development is the same, but 

 the difference between the percentages in both forms is 

 considerable enough — in c and d at least - — to be em- 

 ploj-ed as a specific distinction. For all this, the forms 

 are so like each other that one may well be tempted, 



remembering the dubious value in the Cods of the 

 characters drawn from the coloration, to explain trdclmja 

 as a short-nosed form, which is, however, more ad- 

 vanced in development, of the same species as navaga, 

 which is apparently always inferior in size to ivachnja". 

 The fin-formula may be I'egarded as identical in both 

 forms, though here, as in several other Gadoid species, 

 we find the peculiarity that in many cases the larger 

 specimens have fe^ver rays in one or more of the fins''. 



Fio-. 120. 



Oail'.is saida, •';^ oi tlie natural size. Arcliangel Fisli Market, 187G; II. S.\ndeberg. 



Another Arctic species, Gadiis sa'ula'', the Polar 

 Cod {Gad 11)^ poJaris) of later authors, comes verv near 

 narafid, but is one of the species that have best claim 

 t(j the Y-Awk of a distinct subgenus''. It has never been 

 found ali\e on tlie coasts of Scandinavia, but occurs 

 pretty often in our Glacial clays, and has thus at no 

 very distant period, geologically speaking, jjclonged to 

 the fauna of Sweden and Norway (fig. 121). 



Tlie most distinctive characters of the Polar Cod 

 lie ill the rapid attenuation of the hind part of the 

 body; the rather forked shape of the caudal fin; the 

 cninparalively great distance (as in Gadiis navaga) be- 

 tween all the vertical fins, the length of the base of 

 the third dorsal fin being at least equal to that of the 

 second dorsal fin; the long paired fins, of which the 



pectoral fins have the middle ravs longest or only 

 slightly shorter than those immediately above them, 

 the great length of the ventral fins being due, as usual, 

 to the filamentous elongation of the second ray; the 

 large eyes; and the prominence (though sometimes only 

 slight) of the lower jaw. ]\Iost writers have l)een in- 

 duced by the last character to range the Polar Cod next 

 to the Coalfish-group; but the character is present, 

 though only slightly appreciable, in the voungest stages 

 of the Common Cod, and the resemblance between the 

 Polar Cod and navaga is too great to admit of any 

 remote separation of these tAvo forms. Again, by the 

 comparatively small number of rays in the first dorsal 

 fin the Pohir Cod is incontestably referred to the group 

 of the true Cods'. The followiiiii- table is calculated 



" According to Pat.las navtii/n is generally nlioiit 7',.^ in. long (■■'jiithamalis), wachiija \o in. (bispilliainalis). TUf specimen oi iiavat/a 

 measured by KuLliEUTErx was. however, 283 iiiiu. (ITS in.) long. 



'■' Gfidus uavctf/a: D. 13| 17 — 20,2 1 — 24 ; ,1. 21— 24|21— 22 ; P. 10 — 20; T'. li; C. x + 2b + x. 



„ <jrijciUs: „ 12 — 1 3 1 — 1<);20— 21 ; ,, 21— 23|20— 21; „ 19 ; „ G; „ ,r + 23— 27+;s. 



' Gudds gaiila, Lepechin, JV. Comm. Acad. Petropol., toni. XVIII (1773), p. 512, tab. V; Pall., Zooijr. 11. Asiat., toni. Ill, \k 19!); 

 (Jmll., N. Nordli.-exped., Zool., Fiskc, p. 120. pi. IV, tig. 33; Bean (Boreojaihis, ex Gtiiu), Proc. U. S. Nat. Mus., vol. IV (1881), p. 243; 

 JoiiP., GiLR., Bull. U. S. Nat. Mus., No. 10, p. 807: Turner, Nut. Hist. Alaska, p. 89, pi. II; Lill.i. (Gadtis), ^u., Nonj. Fii., Fisk., vol. 

 2, p. 103. (Indm cetjlefinus, Faur., Fii. Groeiil.. \i. 142. Merhuiyns j^otaris, Sab,, jSiijipl. App. Parry's Fii'-H Voi/., p. 211 ; Kichakds., 

 Fn. Bor. Arnci-., part. Ill, p. 247; NiLSS., ;Sk(tnd. Fii., Fisk., p. 969; Gill. (Boreogadiis), Proc. Acad. Nat. Sc. Pliilad. 1863, p. 233; 

 Mors, Ofvers. Vct.-Akad. Fori). 1864, p. 531. Gadns Fabricii, PiCHARns., 1. c, p. 245. Gadiis agilis, Rhpt, D. Vid. Selsk. Math. Naturv. 

 Afii., Deel 7, pp. 115 ot 126; NiLss., 1. c, p. 568. Gadas glacialis, Peters, Za\ Th-ulsche Aordjwlarfahrt, lid. 2, p. 172. 



■' Bort'ogniliis, G-riiR, Vat. Ih-it. Mns., Fish., vol. IV, p. 336. 



■■ In Gadii.'i saida the lin-forinula according to our investigations is: D. 12 — 13|14 — 1 8, 18— 22 ; .1. 15 — 19,19—22; /'. 18 — 19; 

 V. 6; C. ,i> + 20—22 +.r. 



