400 



SCANDIXAVIAX FISHES. 



The nostrils resemble those of the Plaice, botli in 

 torin and position; but the anterior are somewhat more 

 distinctly incised in an oblique direction at the top, 

 and their pointed marginal flaps are somewhat longer , 

 and more distinct. The eyes are set on the left side, 

 at least half as often, if not in quite so many cases, as | 

 on the right. Their position is the same as in the 

 Plaice, but their size is less. In specimens between 

 about U) and 2Ci cm. long the longitudinal diameter of 

 the eve is about l(i or 17 % of the length of the head, 

 and in specimens between 29 and 3"2 cm. long about 

 15 or 14 %. 



In this species also, the body is furnished \\ith 

 cvcloid scales, imbricated only at the end of the tail 

 and on the base of the caudal fin, and these smooth 

 scales are more or less deeply imbedded in the thick 

 skin. But their occurrence is confined, in ordinary 

 cases, to the intervals between the spaces covered by 

 sharp, spinous scales. Sometimes they are scarce, or 

 may even be wanting on certain pai-ts of the body. 

 The spinous scales are either ordinary ctenoid ?;cales, 

 with spines onlv at the hind (free) margin, or trans- 

 formed into spinous warts. \\-\\\\ erect spines all round 

 their surface. These scales or warts occur on both 

 sides of the lateral line and on the head; but their 

 number is verv different in different specimens. In 

 some cases thev are scattered over the ^vhole of the 

 coloured side of tlie bod^■, tliickest, however, at the 

 sides of the lateral line. On the blind side they ap- 

 pear generallv at the lateral line and seldom on the 

 liellv. The greater portion of the blind side of the 

 head is alwavs naked. At the base of each fin-ray, 

 but set in the spaces between the roots of the rays, 

 both in the dorsal and the anal fins, we find a lar^e 

 spinous wart. This row of warts seldom extends, 

 however, to the end of the fin on the tail, and 

 in most cases it is double on the anterior '^ixvX of 

 the body. In some cases the body is entirely smooth, 

 with the exception of the spinous warts at the bases 

 of the dorsal and anal fin-rays and a few on the 

 head and at the lateral line. This is the case with 



the variety brought home from Archangel bv Lieute- 

 nant Sandeherg and described under the name of P/('»>o- 

 nectes Boinhinorii. of which eqnalh- tvpical specimens 

 may be found in the Baltic. Among the varieties of 

 tiesHs this form is evidenth- a deviation in the opposite 

 direction to That taken among the varieties of ^(/rtfessff 

 by psei(dofle^iis : and thus the two sjjecies approach each 

 other in their varieties. 



The lateral line, which begins at the bent, osseous 

 ridge on the head, forms a curve that is often scarcely 

 perceptible, above the pectoral fin, and then runs straight 

 out to the extreme tip of the middle ray of the caudal 

 fin. (^)n an a\erage we find 76 pores in this line on 

 the body, and 26 on the caudal fin. 



The dorsal fin begins, as in the preceding species, 

 above the upper eve, but ends at a distance from tlie 

 caudal fin tliat uiaA" sometimes be equal to tlie least 

 depth of the tail, and is at least 80 % thereof or 35 — 4() 

 % of the postorbital length of the head. Tlie base of 

 the dorsal fin as a rule occupies about 77 — 8o % (some- 

 times as nuich as 86 %) of the length of the body to 

 the base of the caudal fin. Its greatest height, which 

 generally occurs between the 27th and 33rd rays (on 

 an averaae at the 30th) from the beoinnino:, is about 

 13 — 16 "o (on an average 14^ „ %) of the length of the 

 body m'diks the caudal fin. All the rays arc simple 

 and scaleless". The anal fin. which is analogous to the 

 dorsal in shape and structure, begins at a distance from 

 the tip of the snout which, in our specimens, is never 

 less than 40 % (in most cases between 41 and 46 %) 

 of the length of the body to the base of the caudal 

 fin. Its greatest height. Avhich occurs between the 13th 

 and 16th ravs (on an average at the 15th), is generally 

 somewhat greater than that of the dorsal fin''; but the 

 length of its base is only seldom 60 % (generally be- 

 tween 51 and 58 %) of the length of the body miuKS 

 the caudal fin. The pectoral and ventral fins essentially 

 correspond to those of the Plaice; but in the former 

 the length of the first rav is more than half, or at 

 least half, that of the second rav or even of the third, 

 which is the longest. The caudal fin is of the same 



" NoRDMAXX (1. c.) states, however, with regard to the Black Sea form, that of 12 specimens 2 were furnished with "ciliated scales 

 on the middle rays of the dorsal and anal fins." In two small specimens, respectively 13 and 14 dcm. long, which Hepexborg has sent 

 home to Stockholm from the Bosphorus. the middle rays of the dorsal and anal fins are also rough with scattered, spiny scales. These spe- 

 cunens are entirely destitute of ctenoid scales on the body with the exception of the usual row of spinous warts — and these are small — 

 along the bases of the dorsal and anal fins, and tlie bony tubercles on the cranial osseous ridge between and behind the eyes. This ridge, 

 by its extraordinary breadth behind, reminds us very much of the Arctic forms which we are just about to describe. 



'' In 12 full-grown speciniens the greatest height of the anal fin measures on an average 15'/., fo of the length of the body minus 

 the caudal fin. 



