870 



SCAXDIXAVIAN TISIIES. 



327, tal). XXV. fig. 4; Gthi;, (',(/. lirit. .Vits., Fisli., vol. 

 VI, p. 1G7. 

 Eperlanns vuh/aris, G.mm., Co//. /,<!/., Groenl., tab. 18, fig. 2. 



In the larf;e.st Swcdisli 1,'ikc, W euci', tlie Smelt 

 frequently attains a length of ;i l'i»it or aliout ;! dm." 

 to the exti'eme tip of the eaudal fin. In Lake i\I;ilai- 

 too it i.s frec|uently of a fair .size, aljout 27 cm. in 

 length'; but in the smaller lakes it seldom exceeds a 

 length of 10 — 20 cm. As we have mentioned above, 

 the Scandinavian fishermen distinguish by size and 

 odour between two kinds of Smelt, calling the lai-ger 

 kind sJom. The line between tiiese two kinds is drawn 

 at a length of about 2 dm. According to Nokback 

 the Smelt 



at a length df abuut Ci cm. weighs about 13 — 17 granmies, 



., „ „ ., „ — 12 ., „ ,, 34 — 43 



„ „ „ „ „ 18—20 „ „ „ 85—127 



♦ „ „ „ ,. V 30 „ ,, ,. 300 



Pennant' .s largest specimen was SM cm. long and weighed 

 227 grammes''. 



The body is rather elongated and of a compressed, 

 fusiform shape, the upper and lower contours being 

 slightly and similarly arched. According to the ri]jeness 

 or emptiness of the sexual organs the greatest depth of 

 the liody, \vhicli is situated at the beginning of the 

 dorsal fin, varies between 14 and 18 % of the length 

 of the body. The greatest thickness, which lies nearer 

 to tlie back than to tlie Iiellv, and is fairly uniform 

 from the opercular region to the dorsal fin, varies be- 

 tween 8 ''2 and 11 % of the length of the body or 

 between 48 and 70 % of the greatest depth. The least 

 depth of the body (of the peduncle of the tail) varies 

 between G (or a little more) and 4' „ ^ of the lengtii. 

 The form of the body is thus subject to considerable 

 variations, and is as a rule deeper in the females than 

 in the males''. The back, including tlie forehead, is 

 broadly rounded, as well as the liclly, \vhicli at the 

 ventral fins even a|)proaches to fiatness. 



The head resembles a compressed cone, the point 

 being formed by the ii\> of tlie lower jaw; and its 

 length from the articular knob of the maxillaries' is 



somewhat less than '^ (21 — 24 %) of tiie length of the 

 body. The convex snout resembles an obliquely cut 

 cone, and consequently the sharp margin of the upper 

 jaw f'oniis an ellijjse. Its length is about 2() — .30 % of 

 thai of the head', the percentage rising \\'ith fair uni- 

 formity' during growth, and its breadth across the 

 articulation of the maxillaries is oidy slightly less. 

 The longitudinal diameter of the eyes is somewhat 

 greater than the vertical, measuring in young Smelts 

 about ' J, in old about ' ,., of tlie length of the head, 

 or in the former nearly '/-, in tlie latter about ' j, ot 

 the lengtii of the head reduced (from tlie articular knob 

 of the maxillaries to the hind margin of the preoper- 

 culum). In the former their longitudinal diameter 

 sometimes is more than \\ greater than their distance 

 from the articular knoli of the maxillaries, in the latter 

 it sometimes sinks to ^/^ of this distance. Tiie least 

 lireadth of the interorbital space increases even rela- 

 tiveh- with age from about 22 to about 28 % of the 

 length of the head, or from about ' 3 to '/. of the 

 length of the head reduced. The nasal cavities lie just 

 behind the articular knob of the maxillaries, the di- 

 stance from the middle of the tip of the snout to the 

 front margin of the anterior nostril l)eing, however, 

 nearly t^vice that from the hind margin of the jwsterior 

 nostril to the front margin of the eye. The two nostrils 

 on each .side of the snout are small, the posterior 

 somewhat larger than the anterior, luit usually covered 

 to a great extent by the backward dermal fold con- 

 taining the thin ridge that divides the nostrils. The 

 intermaxillary bones are about equal in length to the 

 eyes; and the length of the maxillaries, which increases 

 even relativelj' with age, varies between about 9 (8',,) 

 and 11 ® of that of the body, between 42 (40'/.,) and 

 50 % of that of the head, or between 62 (60) and 67 

 ?i. of that of the head reduced. The supplementary 

 (jugal) ])one of the maxillaries is behind lancet-shaped, 

 in front elongated to a point. Its anterior [lart lies 

 loose in the dermal fold uniting the maxillary l)one to 

 the cheek. The lower jaw is of a flat, boat-like shape, 

 in front curved uniformly, l)ut rather slightly upwards. 



" Tenow gives even 4 dm. (See Vermlamh och Dais Ryggradsdjur, p. 108). 



'' Underd. Bet. in. Ftirsl. t. Fiskeristadga 1883, p. 158; Lilljeborg, 1. 0., p. 031. 



' Brit. Zoo\. (London 177G), p. 274. 



'' In Osmerus dentex and 0. spirinclins the sexual difference seems to be reversed. Cf. Smitt, 1. c., p. 171). 



"■ For the sake of uniformity in a comparison with Coregomis we have measured the length of the body etc., licre as in Rtlsmiiseets 

 Sahnonider (1. c), from the articular knob of tlie maxillaries, and not from the middle of the tip of the snout. 



f In Riksmuseets Sahnonider tlie length of tlie snout in the Smelt is measured from the articular laiob of ilie maxillaries, and there- 

 fore less. 



