i-'i.ri\i;s. 



453 



EKSTROM's TOPKNOT (sw. smaiivakfven). 

 SCOl'HTIIALMUS NUKVEGICUS. 



Plate XIX, fig. 1. 



Greatest depth of the l)ody less than 40 %, total length of the head less than 25 %, length of the head behind 

 the loirer eye less than 14 %, niaxillari/ hone of the eye side less than 10 %, maxillary hone of the hlind side less 

 than 9 %. branches of the loirer j((tr less than 12 %, pcctor(d Jin of the hlind side more than 8 %, hase of the 

 dorsal fin {measured in a straight line) less than 75 %, its yreatest height {longest ray — 5Gth — 59th) less than 

 11 %, base of the anal fin less than 05 %, its greatest height {about the 43rd or 44th ray) less than 11 %, the 

 distance between it and the tip of the snout less than 23 %, length of the middle rays of the caudal fin more 

 than 14\^ %, greatest thickness of the body more than 7 % — in each case relatively to the length of the body. 

 Length of the pectoral fin of the blind side more than ''/r, of that of the lower jaw on the same side, and the 

 length of the middle caudal rays more than Vs greater than that of the lower jaw and also more than 'A, the 

 length of the head. Least depth of the fail more than 17 % of the greatest depth of the body. 



R. hr. 7; D. 74—83; A. 63—68; P. sin. 10, dextr. 7 1. 8; 

 V. 6; ('. 2 + 12 + 2 1. 3 + 10 + 3; Lin. lat. 50 1. 51. 



,%/!. Pleuronectes Cardina, Fr., Vet.-Akad. Handl. 1838, p. 184 

 (excl. synon.) nee Cuv. ; Sundev., Skaiid. Fisk., ed. I, p. 200, 

 tab. 50; NiLSS. (Rhombus), 6'kand. Fn., Fisk., p. 643. 



Rhombus norcegkus, Gthr, Cat. Brit. Afiis., Fish., vol. IV, 

 p. 412; Coll. {Zeugoplevns), Porli. Vid. Selsk. Christ. 1874, 

 Tillsegsh., p. 139; ibid. (Lepidorhombus) 1879, No. 1, p. 77; 

 N. Mag. Natiirv. Christ., Bd. 29 (1884), p. 100; M.4lm 

 (Rhombus), Gbgs, Boh. Fn., p. 518; Lillj. (Zengopterus), 

 Sv., Norg. Fiskar, II, p. 336. 



Ekstrom's Topknot, Couch, Fish. Brit. Isl., vol. Ill, p. 175, 

 tab. CLXVII. 



Ob.<. Cl'VIEr's Pleuronectes (Rhombus) Cardina is clearly a 

 couibiiiation of Scophthahnus, to which he refers in his quotation of 

 DUH.4MEL (Tr. Peches, sect. IX, pi. VI, fig. 5), and Lepidorhombus 

 xvliiff, as Bhown by his quotation of Ray (iSijn. Pise, p. 163, pi. 1, 

 No. 2). Fries, too, regarded Scophthalmus norvegicus as identical 

 with Sc. nnimacitlatus (Bloch's Topknot). 



EkstrOm's Topknot fully deserves tlie Swedish name 

 (= Small Fluke) gi\en it by Fkies and Sundevall. Its 

 maxinuini length is apparently about 12 cm. The 

 largest specimen ever found in Scandinavia was 117 

 mm. long. Thus, to the best of our knowledge at 

 present, it is the smallest Scandinavian Flatfish. The 

 body is of a regular oblong shape, elliptical but elon- 

 gated and narrow at the head and tail. The greatest 

 depth, which increases even relatively with age, varies 

 between 31 '/a and 37 V ^ % of the total length of the 

 body, or between 37 and 45 % of the length of the 

 body minus the caudal tin. Tiie snout forms a slightly 

 rounded angle of somewhat less than 90°. At the 



upper eye there is a slight depression in the profile 

 of the head (see the preceding species), but the lower 

 jaw, with its feel)ly marked chin, projects beyond the 

 ellipse in a rectilinear, obtuse angle. Behind the ter- 

 minations of the dorsal and anal fins the tail forms a 

 section of uniform depth, measuring about '/j (18 — 23 %) 

 of the greatest depth of the body, and almost as long- 

 as it is deej), this Ijeing one of the most prominent 

 distinctions between this species and the Whift". 



The length of the head is between 23'/2 and 22^/2 % 

 of the total length of the bodv, or between 28*/, and 

 26'/, ^* of ^he length of the body to the base of the caudal 

 fin. Its external form we have just described. The 

 eyes are set close together on the left side. They are 

 oblong and very prominent, the upper being somewhat 

 larger tlian the lower, and situated a little l)ehind it, 

 close to the depression in the upper profile of the head. 

 The lower eye is set close to the mai'gin of the jaw. 

 Tlie iris and ))iipil are simple, of normal shape, and 

 without any intruding lobe from the former into the 

 latter. The narrow and terete interorbital space (the 

 projecting ridge between the eyes) forms a carina, ^vhich 

 follows the curve of the margin of the lower eye from 

 the middle of the side of the upper jaw, and then 

 coasts the margin of the upper eye, vanishing behind 

 tliis point. The nostrils resemble those of the rest of 

 the Bothoids: the openings are small, a little way apart, 

 with high, soft margin, wliicli in the anterior nostril 

 is tubular and obliquely truncate, and behind elongated 



