528 



SCANDINAVIAN FISHES. 



the end of August, wlien tlie Lirva is between S'/j and 

 9 mm. long, the embryonic vertical tin is still almost 

 continuous (fig. 124), only the hind extremity of the 

 notochord projecting obliquely upwards in the form of 

 a boundary between the eventual upper and lower parts 

 of the fin. The most remarkable peculiarity lies, how- 

 ever, in the situation and form of the ventral fins. 



ll V 



Fig. 124. Larva of Molua mohui, about 5 times the natural size. 



After M'Intosh and Prince, p, the pectoral fin; v, the ventral fin; 



d, the dorso-caudal fin; c, the ano-caudal fin. 



These fins are inserted behind the perpendicular from 

 the insertion of the minute pectoral fins, and their 

 length is nearly half that of the body, but they con- 

 tain only four rays. No barbel can be detected under 

 the chin. The irregular transverse spots, formed by 

 scattered pigment-cells, remind us of the more distinct 



in a line with the middle of the eye straight back round 

 to the base of the caudal fin-rays. The pale ventral 

 surface bounds it inferiorly, while dorsally a stripe with 

 a beautiful opaline lustre runs from the tip of the snout 

 over the eye backward to the liase of the caudal rays. 

 The latter band is opa(jue white on the tail, and it 

 gives the fish a charactei-istic appearance. The dorsal 

 line from the brain backward is distinguished by a 



Fig. 127. Young specimen of Moliia molva. Natural size. 

 After M'Into.sh. 



narrow edge of dull orange or pale olive, and this brings 

 out in relief the colours formerly mentioned." Both 

 the dorsal fins display the black spot at the end. At 

 a length of from 19 to 23 cm. at wliich period the fish 

 is met with on rocky shores, its appearance is entirely 

 changed (fig. 127). It is then marked with transverse 

 spots of brown, both on the sides and on the back, 



Fig. 125. Older larva of Molua molva, about 5 times the natural size. After M'Intosh and Prince, p, the pectoral fin; v, the ventral fin. 



transverse bands in the larva3 of the Cod. In a spe- 

 cimen 20 mm. long (fig. 125), taken at the same time 

 of }'ear, the barbel has begun to develop, and all the 

 vertical fins are separated from each other; but the 

 relative length of the ventral fins has only slightly de- 

 creased, and their insertion is still behind that of the 



Fig. 12G. Young specimen of Molua laolva. Natural size. 

 After M'Intosh. 



pectoral fins. These changes of growtln proceed from 

 this point according to the i-ules laid down above, but 

 a greater interest is attached to the sub-sequent changes 

 of colour in the young Ling. At a length of 9 cm. 

 (fig. 126) the body is marked with longitudinal stripes: 

 "an olive-brown l)and passes from the tip of the snout 



the latter spots extending out over the basal part of 

 the second dorsal fin; and the opalescent stripe of the 

 preceding stage appears as a dentated band l^etween 

 the two rows of spots. The coloration was entirely 

 different in two fresh specimens, respectively 40 and 

 50 cm. in length, which in November, 1889, were for- 

 warded to the Royal Museum from Stromstad by Mr. 

 C. A. Hansson. The smaller of these two specimens 

 is the original of our figure (Plate XXVI, fig. 2). The 

 ground-colour of the body is now I'eddi.sh brown above 

 and milk-white below. The orange or pale olive colour 

 of the dorsal line in the fry has now extended over 

 both the dorsal fins, which are edged with yellowish 

 white, and each furnished with a Ijlack spot lx4iind. 

 This s])ot is more or less distinctl}' continued in a for- 

 ward direction along the margin of the fin, below the 

 white edge, b)' a dark band, Aviiich is either uninter- 



