29 



In the full-grown embryo, the dark, blue-l)lack colour extends from the region above the snout (beginning a 

 few centimetres aboTe the beak-furrow) over the whole of the back, — with large or small patches of a lighter shade every 

 here and there, — and stretching out over the whole of the dorsal surface of the tail-fin. The lower boundary of this dark 

 shade of colour is from the angle of the mouth to the axil, and backwards along the lower part of the flanks on a level 

 with the shoulder-joints, as far as the region behind the anus, where it also includes the ventral portion of the post-anal 

 segment of the body. The pectorals, the dorsal fin and the tail-fin are the darkest parts. The unpigraented or white 

 portion ot the body extends from the snout a little above the beak-furrow, over the whole of the lower jaw, the chest and 

 the abdominal surface, ending in a point behind the anus. From thence it runs as a greyish white colour with darker patches, 

 along the ventral ridge of the tail, spreading out in a lighter shade over the inferior (ventral) surface of the tail-fin. 



The light patches and shades peculiar to this species are distributed in the following manner in this embryo. An 

 oval j)atcli on the back of the neck on each side of the lilack medial streak, extending from the crown of the head 

 (immediately behind the nasal orifice) to a spot on a level with the pectorals, i. e. about midway between the nasal orifice 

 and the dorsal fin. The side-patch previously mentioned as being found on the smaller embi'yo, is also strongly marked 

 on the full-grown one. but on the latter, broken by darker shades and slightly marbled, it extends from above the pectoral 

 to tlu' region surrounding the eye, without however having the distinct limit characteristic of the full-grown animal. A third 

 characteristic lighter part is the lumbo-caudal patch v.hich includes a large part of the sides of the posterior half of the 

 liody. It spreads from the middle of tlie body (on a level with the dorsal fin) over tlie front portion of the post-anal segment, 

 with a delicate light shade under the post-anal dorsal comb. 



A small portion of the fætal membranes was hanging to the full-grown embryo. The umbilical cord measured 52 

 centim. in length and from 1.5 to 2 centim. in thickness, with few twists and only one or two small prominences here and 

 there. The allantois might be traced as a hollow, cylindrical, thin-walled string into the umbilical cord, and peripherally a 

 little of the expansion of its cavity along the inner surface of the chorion to both sides of the umbilical vessels. The uterine 

 surface of the adherent pieces of chorion was very uneven. At first sight it gave the impression of a very rough, wrinkled 

 piece of serge, the whole surface, which lay in long folds, being thickly covered with either leaf-like, or more rounded, fringed, 

 wart-like prominences, which represented the chorionic villi. On the foetal surface of the chorion might be seen with the 

 naked eye a thick ramification of vessels, covered, to a great extent, by the amniotic sac, with a little subchorionic tissue 

 between. The actual tissue basis of the chorion was very thin. 



