1905-6.] On Delphinns aeutus from Coast of Sutherland. 311 
behind the tip a groove was seen, which extended backwards on 
each side of the beak for 5 inches, and marked off a narrow ledge 
below and in front of the convexity of the head. From this groove 
the head, at first somewhat flattened laterally, ascended with a 
gentle curve to the blow-hole on the top of the head. The lateral 
flattening of the head contributed to give the pointed form 
anteriorly. Behind the blow-hole the back was rounded from side 
to side and the body had the greatest girth. The dorsal fin was 
sickle-shaped and projected vertically from about the middle of the 
back. Behind this fin the back was keeled, and preserved this 
character as far as the tail ; the width of the body also gradually 
diminished and became flattened laterally. The belly was also 
flattened in the greater part of its extent, but was keeled for a 
short distance in front of the tail. The caudal fin consisted of 
two horizontal flattened flanges separated by a mesial notch, and 
its posterior border was concave. The flipper was flattened on 
its two surfaces ; the anterior border was convex, the posterior a 
little concave, the tip pointed. 
The palpebral fissure was If inch behind the angle of the 
mouth ; the auditory meatus, so minute as to be seen with diffi- 
culty, was If inch behind the palpebral fissure. The mouth-slit 
was 8f inches long. No hairs were seen on the skin of the beak, 
or on that covering the symphysis of the mandible. The blow- 
hole, If inch wide, was 7 inches from each eye, crescentic in shape, 
with the concavity directed forwards. The dolphin was a female, 
and the genital fissure was 4f inches long ; on each side a narrow 
mammary fissure f inch long was situated. A small anal orifice 
was placed If inch behind the genital fissure. The umbilicus 
was 13 inches in front of the same fissure. 
Colour . — The beak was glossy black to the tip and sides of the 
upper jaw ; the dorsum and the sides of the head, the back and 
upper part of the side of the body, the upper surface of the tail 
as far as its concave border, the dorsal fin and both surfaces of the 
flipper were also a rich black. A long light-coloured band, pointed 
at its anterior end, situated on the side of the body, commenced 
below the dorsal fin, broadened as it passed backwards, and at 
about half its length was 2f inches wide, when it narrowed for 
some distance and terminated behind, 9 inches in front of the 
