Ad. s. Je.nsen: The Selachians of Greenland. 17 



sharks-teeth fastened in a furrow in the edge of a blade of wood (cf. my 

 fig. 3 a) »). 



General Distribution. The Greenland shark has its proper home and occurs in 

 large quantities in the northern Polar Sea at Greenland, Iceland, northern Norway, Bear 

 Island and Spitzbergen. In the eastern Atlantic it is still common at the Færoes; it 

 is sometimes taken at Scotland, but it seldom extends to England and North France' 

 it occurs on the Murman Coast and in the White Sea, and it follows the whole of the 

 Norwegian coast, though decreasing in numbers towards the south, and from the Skager- 

 rak it enters into the northern part of the Kattegat. Further, it occurs in the northern 

 Pacific (the Aleutians, occasionally Japan, the west-coast of North-America from Alaska 

 to Oregon) and in the North American Polar Sea ; along the east coast of America its 

 distribution extends down to Cape God. 



Raja radiata Donovan. 

 {Raja fiillonica Fabricius (non Linné), Fauna Groenl., 1780, p. 125). 



English: Starrij Ray. 



Danish : Tærbe. 



Greenlandic : Taralikisak. 



West Greenland: From earlier years the Zoological Museum possesses 7 speci- 

 mens of this ray (2 larger, S and ?, 2 smaller, S and $, 2 very young, ^ and ?, as also an 

 embryo in the Qg^)\ they are all only marked in general "Greenland". More recently 

 5 specimens have been received, namely, a male, which is the largest of all and measures 

 555 mm, from "South Greenland", 2 young females from the Davis Strait off Holsteins- 

 borg, 88 fm., a young female and an embryo^) from Holsteinsborg and a young female 

 thrown up on land at Godthaab. 



') J. Steenstrup: Sur I'emploi du fer météorique par les Esquimaux du Greenland. Con- 

 grés internat, d'anthropologie et d'archéologie préhistoriques. Compte rendu de la 6e session, 

 Bruxelles, 1872 (p. 248 & pi. 25, fig. la-b). 



■-) This embryo, which has a total length of 130 mm. behind the dorsal fms has a thin tail- 

 end of no less than 27 mm in length. In Malm's figures of embryos of Raja clavata (Bidrag til 

 kånnedom om utvecklingen af Rajae. Ofvers. K. Sv. Vet. Akad. Forh. 1876, t. III, figs. 3 & 4) 

 we also see behind two rudiments of the dorsal fins (m and n) atail-end of considerable length. Malm 

 has remarked on this unusual position of the dorsal fms far forward on the tail and assumes that "these 

 (viz. the fin-like skinfolds) are resorbed, and that, in a more advanced stage, the permanent dorsal 

 fins, in the vicinity of the tip of the tail, are evolved frorn the lower skin-fold that is to be found there" 

 (1. c. p. 98). On the above embryo of R. radiata, however, the dorsal fins are fully formed, so that 

 no reabsorption of them will take place; I imagine rather, on the other hånd, that it is the larval 

 tail-end lying behind the dorsal fms that is shortened. Further, the following condition has to be 

 considered. In the adult rays on each side of the tail there is a horizontal fold of skin, which 

 only terminates close in front of the end of the tail; in the present embryo there is a similar mar- 

 gin of skin, but it ends some few mm. behind the dorsal fins; this also indicates, that the greater 

 part of the end of the embryonic tail is meant to be reduced. So far as I know, no investigation 

 has been made into this interesting feature in the development of the Raja embryo. 



3 



