IG Proceedi7igs of the Royal Physical Society. 



The ibllowing points were noted in the colour of the 

 skin : — In the adult female the top of the head and the back, 

 as far back as the dorsal fin, were black. Behind the dorsal 

 fin the keeled lunibo-caudal ridge of the back was greyish- 

 white, lighter indeed in tint than the side of the body imme- 

 diately below it, but not so light as the belly. The belly 

 generally was white, mottled with grey, but between the 

 pectoral limbs and in the submandibular region it was 

 almost pure white. The sides of the body were a dark grey, 

 approaching to black, about the middle of its length, but 

 becoming less dark towards the sides of the lumbo-caudal 

 region. Both surfaces of the caudal fin were black, though 

 with a greyish patch on the ventral keel. The dorsal fin was 

 black. The pectoral limb was black on both surfaces, but 

 with a slight greyish patch near the root of the anterior 

 border. The head behind and immediately below the eye 

 was a dark grey. The skin covering the mandible was 

 whitish-grey, but almost white at the angle of the mouth. 

 The skin of the tip of the beak, and that covering the sides 

 of the upper jaw, was white, though with a grey tint, and 

 with a darker patch at the middle of the tip of the beak. A 

 distinct groove, 2| inches behind the tip, differentiated the 

 anterior end of the beak. It extended backwards for some 

 distance so as to mark off distinctly an upper lip from 

 the side of the face. The white grey-tinted patch was not 

 limited to the beak in front of this groove, but extended for 

 about an inch behind and above it. Tlie outline of the head 

 ascended in a gentle slope backwards to the blow-hole. The 

 mouth slit ran backwards almost in a straight line. The 

 falciform dorsal fin ascended from almost the middle of tlie 

 back, though its anterior border was much nearer to the tip 

 of the beak than to the mesial notch in the tail. 



The young male in its general scheme of colour approxi- 

 mated to the adult female, but with certain differences. The 

 back for some distance behind the blow-hole was yellowish- 

 grey on each side of the middle line, but in the middle line 

 a dark brown patch extended forwards almost to the blow- 

 hole. The belly was almost pure white, with scarcely any 

 grey intermixed. The sides of the body were light-grey, 



