8 SMITT, ON THE GENUS LYCODES. 



Here it is of interest also to see, how evenly the iigures 

 for h/,i % in the wliole VahlH-gTowp (from gractUs to the ty- 

 pieal Valilii) are enlarging, in the iirst place owing to the 

 evolutional law (&/„ % juv. < &,„ % sen.) but with the figures 

 for cfracilis, although for a more advanced age, smaller than 

 the others, in accordance with the above stated fact that 

 this form represents the juvenile stages of the group as a 

 whole. 



II: Position of the anal aperture (m; u^; v; v^; fr). 



The position of the anus itself is not given here directly, 

 because with the looseness of the tissues it is often difficult 

 to fix either the anterior rim or the centre of the aperture, 

 but instead of this I have given the position of the begin- 

 ning of the anal fin, what practically will give the same 

 results. 



As above quoted from Reinhardt, the two species or 

 groups of forms of the northern Lycodes may be characterized 

 by the resp. relations between the length of the fore-body 

 (head and abdomen) and that of the tail (here measured from 

 the beginning of the anal fin resp. to the tip of the tail-fin 

 or of the tail itself). Now, in our tables of measurements, 

 as the specimens are distributed into these two groups, if we 

 set aside the larval specimens (with the total length less 

 than 60 mm.), we find, that the lowest figure for the length 

 of the fore-body in the retkulatus-gTow^ (Table III), measured 

 from the tip of the nose, is 44.^ per cent of the total length 

 {"la^Å), while in the Fa/iZii-group (Table II) the highest cor- 

 responding figure is 43.8. In the same manner that length 

 of the fore-body measured from the tip of the lower jaw (i<,) 

 in the reticulatus-grovi^ presents the lowest figure 42.4 and 

 in the Valilii-grow^ the highest figure of 42. o % of the total 

 length ("'/rtfo)- ^or the length of the tail these relations of 

 course in general are reversed. If measured to the tip of 

 the tail-fin, in the reticulatiis-gvou^ the highest figure for this 

 length is 56.2 %, while in the Fa/??n-group the lowest figure 

 is 56.1 % of the total length (7a %); and, if measured to the 

 tip of the tail itself (without caudal fin), this length in the 

 retkulatus-gmvi-^ (Table III) has the highest figure 53.8 %, in 

 the Vallin group (Table II) the lowest figure 54.3 % of the 



