24 Mindeskrift for J. Steenstrup. XXX. 



North Greenlandic rays, that they must just be considered to belong to Raja hyperborea. 

 Regarding the colour for example it is stated, that the colour in all specimens was uni- 

 formly brown on the upper surface; below, in both the larger specimens white on the 

 snout and middle of the belly, dark spots on the sides and a white longitudinal streak 

 extending downwards over the pectoral fms; in the smaller specimens only the snout 

 was white, the rest of the under surface was coloured brownish. This dark colour of 

 the belly points with certainty in the direction of Raja hyperborea, and Vanhoffen is 

 mistaken when he writes, that the colour in the two species is the same; Raja radiata 

 is precisely (as a rule) white over the whole under surface. 



Vanhoffen writes further, that in his North Greenland rays there were three larger 

 spines on the shoulder instead of two as in Raja radiata. The faet is however that Raja 

 radiata — probably constantly — has two spines on the shoulder, whilst Raja hyper- 

 borea as a rule just has three ^). 



Again, the relatively considerable size of the North Greenland specimens should 

 also lead one to think not of Raja radiata, whose maximum length lies about 600 mm. 



Lastly, Vanhoffen writes that Raja hyperborea is distinguished at the first glance 

 from his specimens by the faet, that the spines of the sides and fms are all considerably 

 smaller than those of the mid line, whilst in Raja radiata a number of the lateral spines 

 approach in size those of the mid line. In reality there is no essential disagreement in 

 this^regard between the two species, but the lateral spines are perhaps more evident 

 in Raja radiata, as the spines are on the whole more strongly developed in this species 

 than in Raja hyperborea. 



Only one thing raised a doubt and caused me to hesitate in referring all Vanhoffen's 



specimens to Raja hyperborea. He states namely, that the number of spines in the mid 



line of the back and tail were respectively 22, 17, 11 and 24; the first and the last num- 



bers agree with Raja hyperborea, the intermediate are far too low for this species. Through 



the kindness of the Zoologicai Museum of Berlin and particularly Dr. P. Pappenheim 



I have however obtained the opportunity of seeing 3 of Vanhoffen's specimens, namely 



the two from Umanakfjord (Ikerasak and Igdlorsuit) and the largest from Jakobshavn. 



It appears now, that the low number of dorsal spines which Vanhoffen gives 



for his specimen from Ikerasak is due to the faet, that a large number of the spines 



have been rubbed off, specially all those of the tail except two, so that their number 



cannot be given; but there have clearly been many more than Vanhoffen notes; 



the specimen from Igdlorsuit has 24 dorsal spines, the large one from Jakobshavn 



has had 27. 



^) The specimen of Raja hyperborea described by Gollett — the only one known when Van- 

 hoffen wrote his paper — was stated to have only two shoulder spines. Gollett however has 

 become aware later, that it can be seen in his type specimen of the species, that the third (inner) 

 spine has originaly been present, but has been quite rubbed ofT (Gollett 1. c, 1905, p. 15). 



