I.VCOIHX.U. 



x 9 



Measurements of L. lugubris Liitk. 



Total length 



Length of the head 



Distance from snout to anus 

 Height over the anus 



The length of the head is thus 18,9% in the females, 22,5 — 23,3 % in the males, of the total 

 length; the distance between the snout and the anus is 40—42,3% of the total length. These num- 

 bers thus agree very closely with those of adult L. vahlii. 



Remarks on the variation of the species. 



From the examination just completed it will be evident that L, vahlii-lugubris-gracilis cannot 

 be regarded as separate species. At the same time, it must be put forward that the members of this 

 chain represent 3 races, each possessing its own geographical and separate region, namely Greenland 

 (L. vahlii tyfiica), Iceland (L. vahlii lugubris), and Scandinavia (L. vahlii gracilis}. 



First of all, there is a remarkable variation in regard to size. The species reaches its 

 maximum size at Greenland to over \l, m. (ca. 52 cm.) long; at Iceland the maximum is 35,5 cm., and from 

 Scandinavia no greater specimen than 19,6 cm. 1 ) is known. Since these measurements are based on a 

 large number of specimens they can scarcely be regarded as resting on chance, but one may believe 

 that the species decreases in size as it approaches the more easterly (and southerly) regions. 



Parallel with this decrease in size there is a diminution in the number of fin- 

 rays and vertebras, as will be seen in the following tabular review. 



Maximum length in mm 



Number of rays in pectoral fin 

 dorsal 

 anal 



Number of vertebra; 



It seems therefore as if the species taken as a whole, reaches its greatest development at 

 Greenland; at Iceland there is already a recognisable decline, and at Scandinavia we meet with tin- 

 species in its most reduced conditions). 



Differences between the sexes. 

 Prof. Collett has observed on specimens from Scandinavia that it is easy as a rule to disting- 

 uish males from females by their relatively longer head. The same is the case in Greenland and 



1 ) Cf. Appendix however, p. 21. 



2 ) Collett gives the number as ca. 120, but this must be due t<> an error in coun 



3) Cf. Appendix however, p. 21. 



