238 



likewise the spines of the preoperciilar. Fine pigment-specks 

 have begun to amass in the places where distinct dark spots 

 will appear later on. 



At a length of 27.5 mm. (fig. 3a&b, plate XI) the last remnant 

 of the larval fin has disappeared. On the caudal peduncle and 

 below the dorsal fins the pigment forms such dark spots or 

 short transverse bands as are also seen in the adult fishes. 

 The osseous tubercles of the skin have also begun to appear. 



In fig. 4, plate XI, a 25 mm. long young one of Cottus 

 scorpius L. is represented for comparison with the above de- 

 scribed young ones of Cottus quadricornis, which as before 

 mentioned (p. 237 , the note) were formerly mistaken for the 

 young ones of С scorpius. The great difference between them 

 will easily be perceived. The body is much shorter, more squat. 

 But especially the pigmentation is quite different, and so char- 

 acteristic that we can thereby immediately distinguish the fry 

 of С scorpius: Across the tail, about between 2°^ dorsal fin 

 and the anal fin , is a dark band formed by closely placed 

 stellated chromatophores; this transverse band broadens out 

 somewhat towards the back, and reaches the occiput as a 

 narrow stripe along the base of the foremost dorsal fin. The 

 margin of the preopercular with 4 spines; on the occiput a 

 spine which is bifurcate at the end, behind the eye a smaller 

 spine. 



In connection with this 1 give the representations of young 

 ones of two other arctic and littoral Cottoids viz. Gymnacanthus 

 tricuspis, and Icelus bicornis. 



Fig. 6, plate XI, represents an 18 mm. long young one of 

 Gymnacanthus tricuspis Reinh. taken in the harbour of Proven, 

 West-Greenland^). A continuous larval fin is still present, but 



*) The date is not given, but a young one of nearly the same size (19 mm.) 

 was taken July 25^^ 1898 (at the island Disko, off Assuk). 



