LYCODIN.-E. 



19 



Measurements of L. lugubris L,utk. 



The length of the head is thus 18,9% in tlie 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 \'ariation of the species. 



From the examination just completed it will be evident that L. vahln-lugiibris-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 typt'ca), 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 '/^ m. (ca. 52 cm.) long; at Iceland the maximum is 35,5 cm., and from 

 Scandinavia no greater specimen than 19,6 cm.') 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 southerl)-) regions. 



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

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



Blaximuni length in mm 



Number of rays in pectoral fin 



— — dorsal 



— — anal 

 Number of vertebrae 



Greenland 



L. vahlii 



lypica 



Iceland 

 L. vahlii 

 lugubris 



Scandina\^a 

 L. vahlii 

 gracilis 



520 



20— 19 



117.— 113 



9S — 90 



116— 112 



355 



196 



19 



■iS(i7)| (19) 1S-17 

 105—103 j 97—95^) 



90 j 86— S4 



105 100— 9S 



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

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

 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 



I) Cf. Appendix however, p. 21. 



-) Collett gives the number as ca. 120, but this must be due to an error in counting. 



3) Cf. Appendix however, p. 21. 



