18/6.] A YOUNG DKLPHINUS ALBIROSTRIS. 681 



passing from the angle of the mouth to the root of the flipper, 

 separated this patch from the white of the throat. The second 

 white patch was much smaller in its area (7 in. by '-'] in.) and not 

 so bright in colour. It was placed at a higher level than the first, 

 and behind it. The third patch was very large (14 in. by 1 in.), 

 and oblong or elliptical in shape. It was placed behind the middle 

 vertical line, and was uniform over its greater part; but as the black 

 shaded into the white, the uniformity of the latter was broken by 

 numerous black or dark grey streaks. It was separated from the 

 white of the belly by a narrow but decided slate- coloured band. 



Head. — The curve from the neck was uniform, but at the same 

 time decided ; and this gave the head a massive appearance. The 

 jaws were wedge-shaped ; and the lower lip projected half an inch 

 further forwards than the upper. Traversing the white snout was 

 a well-marked furrow or groove, which commenced at the oral fissure 

 close to the angle of the mouth, and passed round the snout to a corre- 

 sponding point on the opposite side. Its depth was greater laterally 

 than in front ; and it served to give the animal a peculiar beaked 

 appearance. From each side of the white snout, about 1 inch above 

 the fissure of the mouth and immediately below the furrow, four 

 strong black bristles projected. They were placed in a straight line 

 and were a j of an inch apart from each other. 



The blow-hole was situated almost in a straight line above the eve. 

 It had the ordinary semilunar form, and was 1 inch in breadth. The 

 eye was protected by well marked eyelids, the fissure between which 

 was about h inch long. Surrounding the eye the integument had a 

 deeper black tint ; and about an inch from it, it was surrounded by 

 a faintly marked circle or ridge, The auditory aperture could not 

 be detected. 



Dentition. — In the upper jaw there were twenty-four teeth upon 

 each side. Those in the centre of the range were the largest, and 

 the anterior were smaller than the posterior. They commenced 

 about \ of an inch from the middle line ; and the first three on each 

 side were not visible above the mucous membrane of the gum, but 

 could be readily felt. Those of the lower jaw were twenty-six in number 

 on each side. The first tooth was placed about } T an inch behind 

 the middle line, and, with the succeeding three, was completely 

 covered by mucous membrane. When the mouth was closed the 

 teeth of the two jaws interlocked ; but the two anterior teeth of the 

 lower jaw had no opposing teeth in the upper jaw. They were 

 conical in shape, sharp and curved, the concavity being towards the 

 tongue. They were freely movable, the greatest range of move- 

 ment heing outwards. 



General contour of body. — This is well seen in the accompanying 

 figure (Plate LXIV. fig. 1); and it will be noticed that, instead of 

 tapering uniformly from behind the dorsal fin to the tail, the body 

 suddenly expands in a vertical direction and then narrows into the 

 part from which the tail springs. This gives a sort of humped 

 appearance to this portion of the animal ; and the hump suggests the 

 idea of a rudimentary dorsal fin. That it is so in reality is rendered 



