574 LÖNNBERG, OBSERVATIONS ON CERTAIN FLAT-FISHES. 



scales of the blind side are close together and nearly cycloid 

 although a little convex. On each of the rays of the dorsal 

 and anal fins there is, stränge to say, ^) only one row of scales 

 corresponding to the anterior row of the rays of the three above- 

 described forms, the posterior one being niissing. These scales are 

 a little thickened, with a shallow groove on soine of them. Very 

 stränge is the fact, that the scales on the operculum of this 

 form are larger than those on the prseoperculum, just the reverse 

 of the State of things on the three former specimens. The co- 

 lour of this, N:o 4 is that of the brill, grayish brown mottled 

 darker and with numerous white spöts, on body and fins. 



The scales of N:o 5 nearly resemble cycloid scales. They 

 are thin and as close together as cycloid scales, overlapping to 

 some extent, but they are not typical cycloid scales because 

 the hindraargin is raised and forms a slight short crest occupy- 

 ing about one fifth to one fourth (or one third) of the visible 

 part of the scale. The anterior part of the visible scale is 

 sometimes entirely unmarked, sometimes it is provided with a 

 shallow groove that gives the scale the appearance of having a 

 circular crest round its visible margin. The scales on the breast 

 are smaller than the others. 



The rays of the vertical fins of this form have two rows of 

 scales. The scales in the anterior rows are thicker and provided 

 with a groove and a crest. Of my five hybrids this specimen 

 comes nearest to the brill as far as the smooth scaly surfaces 

 go. The colour is that of a dark brill with numerous dark 

 spöts but no white ones. 



The first ray of the dorsal fin resembles almost exactly the 



Fig. 1. corresponding one of a genuine turbot, as it is only 



indistinctly branched at the tip, where it shows 

 three short filamentoid appendages. (Fig. 1). The 

 second and third rays are enclosed in the skin. 

 These three rays are all short and smaller than 

 the immediately following ones. 

 ^) As both parent-forms have two rows. 



