granular substance, and what appeared to be fat or oil globules. Partly embracing
the corpus luteum vesicle was a broad stripe of pale-coloured tissue (fig. 11, ph.),
which ran towards the centre of the ovary, divaricating and thinning, and latterly
terminating deeply in stellate areas. In this pale band, several cavities of different
sizes and shapes existed, bearing a resemblance to empty Graafian follicles. The
tissue forming this pale band differed in nature from the cellular stroma, being
made up of a basis of homogenous structureless membrane, and imbedded in this
was a multitude of elongate or oat-shaped nucleated fibre cells closely resembling
the contractile fibre cells of unstriped muscular tissue. Other pale bands and
streaks similar to what has been above described traversed the ovary at different
points from its circumference centripetally, and some of the finer streaks joined
others, forming a sort of irregular net-work of thin white lines distributed throughout
the stroma generally.
The foetus o f Orcella brevirostris (Plate XXXIII, fig. 1) : a female, is moderately
elongated, with a roundish head and the body laterally compressed behind the dorsal
flipper, the posterior margin of which is on a line with the anterior end of the vulva.
From the margin of the upper lip the head is rounded off to the blow-hole, and there
is no projection of the upper lip as in Globicephalus, but the tip of the lower lip is
slightly anterior to that of the upper. The sides of the head anterior to the eye are
flattened. The greatest swelling or rotundity of the head occurs over the eye. The
mouth arches upwards, until at its angle it is in front of the eye, but at a lower
level. On each side of the snout, 0"-50 above the lip, there is a more or less longitudinal
line of moustachial hairs (h) on either side of the head, four on the right and
six on the left, each hair being separated by an interval of about 0",20 to 0"-28, and
being about 0"-50 long and of a brown colour, and situated in a little pit. The most
posterior hair is 1*75 inch from the angle of the mouth.
The eye is well developed and shows indications of eyelids, but there are no
traces of eyelashes. From the inner canthus a depression curves upwards and
forwards, and a deep pit occurs in the canthus corresponding to the opening
of the lachrymal duct. A furrow also courses backwards from the posterior
angle.
The external ear is a very small crescentic orifice, the convexity being directed
forwards. I t is nearly on the level of the angle of the mouth and 2-60 inches
distant from it.
The blow-hole is a crescentic orifice placed transversely and slightly to the
left side ; the convexity of the crescent being backwards and a little anterior to the
inner angle of the eye. In a straight line, its centre is distant 3 inches from the
tip of the upper lip.
The pectoral flippers are moderately long and broad, but pointed, and about
equalling in size a caudal flipper. Their free border is sinuous corresponding to the
projections and intervals between the fingers, and the anterior margin is the outline
of the half of an elongated oval. Their hinder border is very short, and concave to
the depression at its origin. Behind the pectoral flippers the belly of course is
indicated by a bulging of the inferior line as far back as the anus, and the back
corresponding to this area is arched but somewhat flattened, and concave over the
spinous processes. The dorsal flipper is somewhat falcate, its posterior margin being
nearly vertical and its upper border rounded and arching backwards and Upwards,
but near its tip slightly downwards to the former. I t lies between the umbilicus
and the vent, its hinder margin being on a line or nearly so with the anterior
margin of the vulva. I t is also situated over the 27th to the 32nd vertebra, its
posterior margin being on a line with the hinder margin of the last-mentioned
vertebrae.
Behind the anus, the breadth of the body rapidly decreases and is much compressed
from side to side, and it has a sharp dorsal and ventral margin which are
prolonged between the caudal flippers to the notch. The upper third of this
portion of the side is marked by a longitudinal furrow, which is prolonged forwards
on to the trunk before the vent. The caudal flippers are rather pointed, and their
outer margins curve somewhat inwards. The longitudinal breadth of the base of
a flipper equals about half its length, and the distance between the tips is 6
inches.
The vulva is a, slit 1"*50 long, and on each side of it are the mammary slits
distant 0"'41 from the opening, their posterior extremities being only 0'7,41 from
the hinder end of the vulva. The slits are 0"'20 long. The anus is separated
from the vulva by a distinct perinæum 0"*41 long, which is the length of anal
puckering.
The tail of the foetus from the vent backwards was bent forwards against the
left side of the belly, and the caudal flippers (¿) were coiled round on themselves ;
the right bending downwards below the body and appearing on the other side, its
tip overlying the base of the left flipper. The latter was bent inwards and applied
over the outside of the right flipper. The dorsal fin was bent downwards by its
base and lay over the left side of the back.
The sides of the trunk from the pectoral flippers to the anus were thrown into
six great folds separated by deep sulci. These latter' did not extend on to thé back
nor on to the belly. Whatever explanation they may have, it is to be observed that
these great folds are confined to the part of the body which is bent. The sulci were
from 0“*50 to 0"-75 in depth. Besides these deep furrows the skin of the belly from a
short distance before the pectorals backwards to the vent and extending on to the sides
was thrown into long wavy convex ridges or folds about 0"’32 in breadth, separated
by very shallow depressions or sulci. On the sides they were shorter than on the
belly, and higher up they were restricted to the intervals between the deep sulci. A
few similar folds occur on the sides and back behind the vent., but they do not
extend any distance. The back is crossed by similar shallow folds which are most
pronounced behind the blow-hole and back of the head, hut they do not reach the
sides of the head.
The foetus with-its membranes emptied of fluid, weighed 23ibs.
The mammary gland of the:foetus is 3'50 inches long.