SCANDINAVIAN FISHES. 



almost in a line with the nostrils of the blind side, and 

 extends back to a point, the distance between which and 

 the caudal fin is at least more than half the least depth of 

 tlie tail, and sometimes only slightly less than that depth. 

 The peduncle of the tail is thus longer than in either 

 of the preceding species. The longest rays of the dorsal 

 fin, the 34th, 35th and 36th from the beginning, are 

 equal in length to tlie postorbital part of the head (about 

 12 % of the length of the body) or a little shorter. Tlie 

 anal fin resembles the dorsal fin, and terminates in the 

 same manner, Ijut begins just behind the perpendicular 

 from the base of the pectoral fins, at a distance from 

 the tip of the snout tliat measures 27 — 33 % (in youth 

 about 26 %) of the length of the body. The anal spine 

 is sharp and pointed. The caudal fin is rounded at the 

 hind margin. It contains 12 or 13 branched rays, and 

 2 or 3 simple rays above and below, the innermost of 

 the latter rays measuring ^/g of the length of the fin 

 and the outermost '^j^. The pectoral fin of the eye side 

 measures "/.. of the lengtli of tlie head or 12 — \\% (in 



young specimens at least 10 %) of the length of the body. 

 It usually contains 10 or 11 rays, the two (seldom three) 

 uppermost simple, tlie others branched, and the thii'd 

 and fourth longest. In exceptional cases this fin contains 

 12 rays". The pectoral fin of the blind side is visibly 

 shorter, and generally contains 9 — 11 rays*, the fifth 

 and sixth being the longest. All the rays are often 

 simple (at least during youth), and this is always the 

 case with at least the uppermost 6 or 7 rays and the 

 lowest ray of all. The ventral fins are still shorter than 

 the left pectoral fin, their length ])eing about 8 % (during 

 youth about 6 %^ of that of the liody. They generally 

 contain 6 simple rays, on the blind side sometimes oidy 

 5, but the penultimate and antepenultimate rays are 

 sometimes imperfectly branched at the ti]3. The third 

 or fourth ray is the longest. 



The number of rays is thus inconstant in all the 

 fins. The following table shows how irregularly these 

 variations appear: 



The rays of the dorsal fin may thus vary between 

 67 and 80" or to the extent of 14 rays, about Vr, of the 

 minimum number; but we have no grounds for regarding 

 these individuals as members of two distinct species. 

 It is remarkable, howevei', that the maximum number 

 of rays in this fin, as well as in the anal, apparently 

 appears in the younger specimens''. 



The scales are fairly large and regularly arranged, 

 being thus easy to count. In the lateral line they are 

 (l('e])ly imbedded, and number about 80 or 90". At the 

 middle of the body there are about 30 scales in an 

 oblique vo\s from the lateral line to the back and 32 



in the corresponding row to the anal fin. They are 

 oblong and so narrow that the}' scarcely overlap each 

 other at the sides, and the naked (outer) part is almost 

 round. At the tip they are truncate, with between 8 

 and 13 (sometimes as many as 20) fine, pointed, uni- 

 serial spines. On the blind side the scales of the hind 

 part of the hoAx have fewer spines, and those of the 

 front part none or only one or t^vo. On the eye side 

 the body is almost entirely covered with scales, large 

 and imbricated, as usual, on the hind part; and only 

 the nasal region and the snout, together with the lips 

 and the greater part of the jaws, are scaleless, while small 



" This is tlie case with tlie two females sent to the Royal Museum from Wisby by Professor Lindste6m. 



'' One of the above specimens from Gothland has 18 rays in the pectoral fin of the blind side. 



'' Aceoiding to Gottsche the minimum may be as low as 65. 



'' Also according to Kroyeh's table, 1. c, p. 299. 



' In diiferent individuals we have found 79, 83, and 90 scales in the lateral line. The arched part of tlie line ends between the 24th and 27th scales 



