Utero-gestation in Trygon Bleekeri. 419 
placenta, (2) a glairy milky or bloody fluid, which he sup- 
posed to be in some way absorbed by the fcetus, and (3) the 
gradual increase in weight of the foetus as gestation proceeded, 
Davy left unsettled the questions (1) of the immediate origin 
of the milky fluid, (2) of its immediate destination, and (3) 
of the direct manner of increase in size of the embryo. 
It has been reserved for the ‘ Investigator,’ thanks to the 
profusion of the Batoid fishes in the warm estuaries of the 
Coromandel coast, to extend and amplify the observations of 
Davy, and to draw a more finished and exact picture of the 
aplacental viviparity of this interesting group. The material 
collected by the ‘ Investigator’ confirms the older observations 
as to (1) the absence of any structural connexion between 
foetus and mother, (2) the presence of a creamy albuminous 
fluid in the gravid uterus, and (3) the increase of the foetus in 
size and weight as pregnancy advances; while it adds to our 
knowledge the following necessary facts :—(4) the presence 
of special secretory glands in the mucous membrane of the 
gravid uterus, (5) the existence of arrangements for con- 
ducting the uterine secretion into the pharynx of the foetus, 
and (6) the presence of the unchanged or little changed 
secretion in the alimentary canal of the foetus. 
As references to original papers are appended, it is not 
necessary here to do more than mention that the above obser- 
vations have been made, and in every instance verified at least 
once, in Trygon Bleekeri, Blyth, Trygon walga, M. & HL., 
Prteroplatea micrura (Bl. Schn.), and Myliobatis Nieuhofit 
(Bl. Schn.). In the first-named species, which was the first 
to come under my notice, the observations were made under 
particularly unfavourable circumstances, and I therefore seek 
an opportunity, in describing a second pregnant female of this 
species recently captured by the ‘ Investigator,’ to make 
some corrections and numerous additions to my original 
report. 
§ 2. The Pregnant Female and the Gravid Uterus of 
Trygon Bleekeri. 
A female of Trygon Bleekeri, Blyth, measuring in extreme 
length, from tip of snout to tip of tail, 9 feet 7 inches, in 
length of disk 3 feet, and in greatest breadth of disk only an 
inch and a half less, was caught in Cocanada Bay (at one of 
the mouths of the river Godévari) on the 12th January last. 
The abdomen was distended, being strongly convex instead 
of flat. 
On opening the abdomen the internal organs of generation, 
32* 
