4 Records of the Indian Museum, [Vor VIB; 
on the posterior half of the rounded body, of alow but distinct 
median ridge on either side of which the body wall is pushed 
slightly inwards forming a shallow concavity. 
The embryo when first obtained, was attached to a large yolk- 
sac, and the whole was floating in a creamy fluid caused in all 
probability by the fragmentation of the yolk as has been described 
by Dean (/.c., p. 41) in the case of Chimaera collier. . 
Unfortunately, it was impossible to examine the embryo in 
detail at the time of its capture and before an opportunity arose 
the embryo and yolk-sac had become separated, owing to the 
rupture of the yolk-duct. 
The embryo had apparently reached very much the same stage 
as that shown in Bashford Dean’s monograph (/.c., plate viii, 
fig. 49). The first thing that strikes one is the extreme length of 
the tail. The total length of the embryo was 63°5 mm. and the 
distance between the anterior end and the anus 12 mm., hence the 
proportional lengths of body and tail are as 1: 4°3. In this respect 
it presents a marked difference from the embryo of Chimaera 
Embryo of Rhinochimaera sp., X 3- 
colliei, in which, according to Dean’s figure (he does not give any 
measurements), the proportions are I: 3'I. 
The head. As in Chimaera the most anterior part of the head 
is not formed by the olfactory region and fore-brain, but by a large 
projection, circular in outline when viewed from the side but com- 
pressed somewhat laterally, which probably represents the rudi- 
ment of the elongated snout of the adult. 
Just posterior to this on the dorsal surface is a second 
rounded and much smaller projection (corresponding to the mid- 
brain) which is apparently not represented in Chimaera embryos, 
and this again is succeeded by a large and very thin-walled, 
semi-transparent projection—the hind brain. 
The olfactory region forms a well-marked rounded prominence 
on the ventral aspect, and the olfactory pits have already become 
separated from the mouth, although a faint surface groove can 
be made out connecting them. Between the olfactory pits in the 
middle line a bilobed projection can be distinguished probably 
corresponding to the underlying rostral cartilage. 
