BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 27. AFD. IV. N:0 4. 13 



In all these respects \ve see, that frigidus comes nearest 

 to the VaJilii-gron]} — althougli in its older age it is here a 

 complete reticulatus — ; but the most interesting- is to find 

 two new facts: the sexual differentiation is the same for 

 gracilis and frigidus (^ > c/") but another (9 < o^) for the rest; 

 and among these latter, in the Valilii-gTou^ the 2)allidiis is 

 the highest developmental stage, in the reticulatus-gvovi^ the 

 siminiidus takes that same position. 



These irregularities suggest the suppositions, that frigi- 

 dus may be a hybrid, and that pollidus as well as seminudus 

 may be in the beginning of differentiating themselves to 

 distinct species resp. from Vahlii and from reticulatus. 



UT. Distribution of the scales. 



This matter I have already treated in the y>Scandinaviau 

 Fiskes:!),^ with the result, that vthe individual variations in 

 this respect seem to be so great that we must abandon the 

 attempt to base the determination of the species upon the 

 presence or absence of scales; and no more reliance can be 

 placed on the proposed determination based on the greater 

 or less extent of the scaly covering in a forward direction, 

 över the trunk and head, in those forms which are furnished 

 with scales at an early age and retain them at all subsequent 

 ages». Nevertheless it is a long-know-faet, cited by Rein- 

 HARDT also, that the scaly covering in the Vahlii-growp is 

 not only more constant but also more extended both forward 

 on the body and outward on the vertical fins. Herewith it 

 follows, that the forms of the last-named group get their 

 scales earlier in life than those of the reticulatus-grox^\). The 

 smallest specimen of Lycodes reticulatus, on Avhich I have 

 seen evident scales, is that numbered 26 in my tables of 



1 pp. 608-G09. 



