Description o f external features (Pl. XXV, fig. 4).—The head is convex from
the blow-hole to the upper lip, hut its sides immediately before the angle of the
mouth are somewhat anteriorly convergent, hut rounded (fig. 5). The gape posteriorly
has a long upward curve. The eye which is well developed, is near the angle
of the gape, and in the adult is placed about one inch above it, with a slightly
downward slope. The ear is nearly on the same level as the angle of the mouth,
and it is extremely small, crescentic, and not measuring more than 0"*12 in diameter.
The posterior margin of the blow-hole is immediately behind the anterior angle of
the eye. The blow-hole (fig. 5) is crescentic and unsymmetrical, being more to the
left than to the right side. There are two slight eminences about one inch behind
the blow-hole. The constriction of thé neck occurs below the ear and slightly behind
it. The pectoral flippers have their bases nearly on a level with the tip of the
snout, and they are triangular structures moderately long and broad ; the breadth
equalling about one-half their length. Their anterior margins describe a gentle
outward curve to the tip of the second finger ; their greatest breadth is attained at
the extremity of the 5th digit, on the proximal side of which their posterior margins
rapidly contract. The centre of the dorsal fin is situated behind the middle of
the body, faking the caudal notch as the hindmost limit of the animal. The
fin is falcate and curves upwards and backwards to a rounded point, below which
the posterior margin is concave. Erom the base of the dorsal fin- posteriorly to the
caudal notch the median line of the back is sharp. The ventral line is also sharp
for'some inches behind the anus. The dorsal and ventral ridges stop short about
five inches from the caudal notch. The caudal flippers are moderately broad with
their posterior margins concave from behind forwards. The mammary slits (PI.
XXXIII, fig. 1, m.) occur on each side of the vaginal orifice at a distance from each
other of 2*75 inches. They are unsymmetrical in position, the left being placed
further away from the vagina than that of the right side. The mammary slits are
about one inch in length, and the nipple of each is almost completely hidden in its
own furrow. Each nipple is about a quarter of an inch long and laterally compressed,
the orifice occurring on the external side of an apical crenated-ridge. The
vaginal opening (fig.l, v.) is 3*25 inches long, and is separated from the anus (fig. 1, a.)
by a distinct perineal interval (fig. 1, pe.) I '*50 in longitudinal extent, an interval
which does not apparently exist to the same degree in Cetaceans devoid of pélvic
bones.
The skin above, generally, is dark slaty-blue, nearly black, and very little paler
on the ventral surface. None of the specimens that have come under my observation
have ever presented those scratch-like streaks on the skin which I have referred
to as occurring in O. jkmmalis. The young have a distinct moustache occurring
about 'one-half inch above the upper lip, and consisting of five brownish bristles ;
the first bristle being placed about one inch behind the tip of the snout, the line
of bristles occupying an area of three-quarters of an inch (Plate XXXIII, fig. 1, h).
The foregoing description was drawn up from a gravid female, the foetus of
which (fig. 1) was nearly fully mature on the 1st June, the date of the death of the
mother. A second female caught on the 16th July, and which proved to be a virgin,
was rather emaciated; the neck being well defined and the angles of the ribs distinctly
indicated. The under surface half-way between the pectoral flippers and
the genital slit was marked by a deep longitudinal mesial furrow fully an inch in
depth, and from the anterior extremity of this a branched depression was prolonged
forwards widening into a rounded hollow over the stémum. The genital slit was
42"*80 from the tip of the snout, and 4"* 20 in length, and the anus was 1 *50
removed from its hinder end. The left mammary slit was the longer, measuring
'¿'-38 in length, and that of the right side was 0"*3S long, the distance between
them posteriorly being 1"*33 and anteriorly 1"*46. The anterior end of the left
slit was 2"*06 from the anterior end of the vulva. The right ear in this specimen
was 0"*08 in diameter, but on the left side it was so reduced that I did not
detect it for some time, and it would hardly admit the passage of a fine bristle. ^ The
moustachial bristles had been shed, but their position was indicated by the pits in
which they had stood.
This example yielded the following girth measurements :
Circumference one inch behind the blow-hole . .. • • ‘ * * '
„ of the neck • • *
i ; „ behind .the pectoral flipper . . . . ' • •' • • *
. n in front o f the dorsal fin . . • • • • ■ * . 2 9 7 5
„ anterior third . . . • > • • • • • * ®
behind the anus ...................................................................... _
„ _ at the root o f the. tail . • • • . • ’ *• .
Distance from angle to angle o f month below . - . • • • ' • •
„ between the pectoral flippers, under s u r f a c e ......................................... ' 9 00
Measwrements o f two specimens o f Qrcella breovrostris.
From tip of snout to caudal notch, alongside
Snout to dorsal fin following curve of back .
Length of the dorsal fin (i. e., antero-posteriorly) ..
From tip of snout to base of pectoral flipper
Length, anterior margin of pectoral extremity
' „ posterior margin of same . . . .
Caudal fin along its anterior border .
Snout to blow-hole over forehead . . . .
Breadth o f the blow-hole . . • , •
Height o f the dorsal f i n ........................................
Across from tip to tip of caudal fin
Depth of the caudal notch . • _• •
Length of pectoral extremities in a straight line .
Greatest breadth of pectoral flipper
From the tip of snout to angle of mouth
From angle of mouth to ear-hole in straight line .
Distance between angle o f mouth and eye .
Length o f the eye . • • , , g • ’
Distance from eye to eye taken round point of snout
1 S c
■ i
inches
82-50 71-00
46-00 42-00
8-00 5‘00
16-50 15-75
17-00 15-75
-12-00 11-52
1600 13-25
10-00 9 1 0
1-60 1-33
3'75 2‘25
21-50 20 00
1-75 1'50
1400 13‘25
6-25 5-75
600 5-75
4-75 4 ‘50
1-63 1-33
0-87 0-67
13-50
Cavity o f the mouth (PI. XXVII, figs. 1 & 2).—The pigment of the external
slcin occurs on the mucous membrane as far as the position of the fraenum linguae,
on the inside of the lower lips, and all over the upper lips and on the palate as far
back as on a line with the angle of the mouth. The lower lip is rounded, but .the