PEOFESSOE FLOWEE ON EISSO'S DOLPHIN. 13 



white, the junction between the two colours being very abrupt, passing from the angle 

 of the mouth above the origin of the pectoral fin backwards to the vulva, behind which 

 the whole of the surface was black. On the sides were several large longitudinally 

 disposed nebulous washes of light grey, the most conspicuous of which was between 

 the pectoral and dorsal fins ; and the lateral surfaces of the last-named fin, especially near 

 its base, were yellowish white. The upper lip, the front surface of the head, as high as 

 the top of the vertical anterior wall of the adipose prominence, and the chin and throat 

 were white, with a distinct yellow tinge. The pectoral fin was black on both sides, and 

 showed none of that peculiar delicate mottling or dappling so conspicuous in the larger 

 specimen. Both surfaces of the caudal fin were black. So much for the general 

 ground-colour, upon which were laid certain markings of a somewhat similar character, 

 though very diiferent in number and in arrangement, to those of the adult animal. 

 On each side of the body were six vertical whitish stripes, nearly symmetrically 

 arranged, and almost equidistant, being about six inches apart. They did not extend 

 quite to the middle line of the body above, and were lost below in the light colouring 

 of the abdomen. These stripes were not so complex in structure as those of the adult 

 specimen, being merely broad white lines, shading insensibly at the edges into the 

 general dark colour" of the surrounding cuticle, and with an obscure dark central line. 

 In addition to these, however, there were three others, which, though short and 

 straight, had exactly the same characteristic formation as the best-marked streaks of 

 the other specimen, having a white central line, bordered first with black and then again 

 with white. These were situated : — one on each side of the narrow part of the tail, close 

 to the upper median lidge, just before the commencement of the lateral expansions of 

 the caudal fin ; and the third obliquely longitudinal, a little to the left of the middle line 

 of the back, just in front of the dorsal fin. This last, especially, was extremely impor- 

 tant, as, being asymmetrical, it showed the tendency to variation in colouring and 

 surface-markings, and so helps to account for the great diflerence in these respects 

 between the two specimens. 



On each side of the upper lip were eight extremely short, whitish bristles, their tips 

 only just projecting beyond the level of the cuticle, arranged in two rows, six in the 

 lower and two in the upper row, as shown by the dots in the figure. There were no 

 similar bristles on the under lip or chin. 



The condition of the teeth was of extreme importance, as helping to establish the 

 normal dentition of the species. There were no teeth visible above the gum in either 

 jaw; and on a careful examination of the soft tissues between the surface and the 

 bone, not a rudiment of any tooth could be found in the upper jaw, while in the lower 

 jaw were the germs of seven teeth — four on the right and three on the left side, close to 

 the S3'mphysis. The crowns of these teeth were conical, pointed, and strongly curved. 

 Calcification had extended rather below the base of the crown or neck of the tooth. 



The skeleton presents all the signs of immaturity which might be expected in an 



