Nr. 9] CONTRIB. TO THE LIFE HISTORY OF THE FISHES 31 



taining an embryo of complete ray-shape. Total lenglh, 94 ram., 

 pigmenlalion on dorsal side complete. The fore end of the head 

 had now grown togelher with the oral disc, forming one united 

 whole, hut the boundary between the blunt fore end of the head 

 and the protruding oral disc still visible. Gill threads have now 

 disappeared. Spines on the dorsal side now indicated; nol onlv 

 the larger ones in the medio dorsal line, hut also the small ones 

 on the disc. All spines covered by the skin, leaving the upper 

 surfa ce smooth to the touch. The yolk sac now reduced to a 

 diameter of 16 mm. Lateral folds of the caudal part developed, 

 reaching a litlle way behind the 2 dorsal fin. The embryonal 

 anal fm still existing, but apparently dwindling. Distance from 

 2 dorsal fin to point of tail 17 mm. The caudal part was curved 

 up along the right side, owing to lack of space, the pectoral 

 fins being for the same reason somewhat folded. The deseription 

 here given applies also to an embryo of R. radiata which I 

 found in the collection of the late curator V. Storm. This is 

 doubtless from Trondhjem Fjord, hut no date or locality staled 

 (pl. II, fig. 7). Total length 102 mm. In this case, however, the 

 tail part is curved up along the left side. Pectoral fins slightly 

 folded at the edges. Yolk sac abt. 18 mm. diameter. Division 

 of the ventral fins far advanced. Here also, Lhe distance from 

 2. dorsal to point of tail was 17 mm. (vide pl. II, fig. 7). I 

 have also a specimen of a similar stage from Stjørdalsfjord, ]8 /2 

 1907. This is shown in pl. II, fig. 6, in its actual position in 

 the egg capsule. It will here be noticed thai the median line 

 of the disc coinsides more or less with the diagonal of the cap 

 sule cavity. The caudal part curved along lefl side, and lhe 

 pectoral fins partly folded. Diameter of the yolk sac abt. 15 mm. 

 Total length of the embryo abt. 103 ram. and distance from 2. 

 dorsal fin to point of tail 17 mm. 



I have no newly emerged specimens of R. radiata in my 

 possession. The smallest free specimens I have measured myself 

 are respectively 170 and 220 mm. total length (pl. III, figs. 11, 12, 

 13). Figs. 11 and 12 show the dorsal and ventral sides of a 

 R. radiata from near Munkholm, 2u /io 1914. It was 170 mm. 

 long. Fig. 13 shows the dorsal side of a specimen tåken at the 

 same place and time. The first was a ?, the second a d* with 

 small pterygopodia. In both specimens the boundary between lhe 

 oral disc and therewith connected flaps of the pectoral fins were 

 visible (pl. III, fig. 12). The embryonal lail end behind 2. dorsal 

 fin is now no longer found, and instead of the anal fin, we find 

 on the under side of the tail a small furrow, as shown in pl. 

 III, fig. 12. 



Professor Collett (Meddelelser om Norges Fiske 1884 — 1901, 



