Bd. V: 6) THE FISHES OF THE SWEDISH SOUTH POLAR EXPEDITION. 63 



This species is closely allied to Myctoplium arctiaim (LüTKEN)' described from 

 off the Greenland coast, but differs from the same in the following point. The 

 number of anal rays is large, about 21, but only 17 in M. arctiaim. AO. are 18 

 in this new species, only 15 — 16 in M. arcticinu, and as already stated the Pre. sit 

 farther apart. The different arrangement of the SAO. is already mentioned. I have 

 not had any specimen of J/, arctician for comparison, but, to judge from Ll'TKEN's 

 figure (1. c. p. 249), it seems to have a considerably wider interorbital space than the 

 new species. The relative dimensions of the head are also different. In a specimen 

 measured by LüTKEN, and of the same size as this one, the length of the head was 

 contained 3V5 times in the total length, and according to a communication, kindly 

 given me in a letter by my friend Professor AuG. Brauer, he has found the rela- 

 tion between the length of the head and the total length in another specimen of 

 M. arctiaim to be i : 3,3. These differences appear to be so important that, if the 

 different geographical distribution as well is put in the scales, there can be no doubt 

 of the specific value of the fish described above. But it is of exceedingly great 

 interest to find that the Greenland seas and the Southern Atlantic are inhabited by 

 two so closely related forms which even show a such biological affinity as the ex- 

 centric situation of the lens of the eye indicates. 



5. Myctophum affine (LüTKEN). 



I specimen caught at the surface where the temperature was + 21,9° C. nth 

 of Dec. 1901. 32° 15' S. lat. 50' 14' \V. long. 



The collection of this expedition contains only a single and small specimen of 

 this species from the mentioned locality. But it is otherwise known to be very 

 widely distributed as already LüTKEN ^ could enumerate many localities from the 

 Indian Ocean. Later the authors of the "Oceanic Ichthyology" could record their 

 M. opalinitm from many other localities in the Northern Atlantic off the North 

 American coast. M. nitidulmii Garman is very similar to this one and, if not 

 identical, it seems to be only a geographic subspecies of J/, affine found in the 

 Pacific: 27° 50' N. lat., 145° 45' 30" \V. 



The above recorded locality appears to be the most south-western where this 

 species has been hitherto collected. 



' Spolia Atlantica. Scopelini, K. D. Vidensk. Selsk. Skr. 6 Rîekke T. VII. Kjöbenhavn 1892. 

 ' Spolia Atlantica 1. c. p. 252. 



