316 Records of the Indian Museum. [VoL. 27, 
the third there were over 20. The cysts were distributed generally 
over the body and were situated in the epidermis. They were 
surrounded with dense black pigment. On opening the cyst a 
milky-white larva was obtained which measured °7 mm. long and 
‘5 mm. broad. This larva was enclosed in a thin, but pigmented 
sac, which was unattached and easily removed. Figures of the 
parasite are given on plate xxvi, figs. 5a,b andc. ‘There was an 
outer, somewhat egg-shaped membrane, which was tough and 
transparent. The contents of this membrane were disposed to- 
wards one pole. A few cells in an active state of division were 
observed, towards the pole. The larva is evidently too young to 
admit of certain identification. 
It is probable that the adult of this parasite will be found in 
fish-eating birds as its host is commonly eaten by them. 
(5) Encysted Cercaria in the superficial muscles of Labeo 
rohita and Catla buc hanani. 
(Plate xxvi, fig. 4). 
Locality.—(I) Labeo rohita and Catla buchanant from Raj- 
mehal, Bihar, India, October, 1913. 
(II) Labeo rohita (other specimens). No history. 
The cysts were smaller but similar in outward appearance to 
those found in Cirrhina latia. They were, however, situated in 
the superficial muscular layer. The two suckers were prominent. 
At present, the identification of these larval forms is impos 
sible. E 
Their occurrence in the muscular tissue of these fish is a fact 
of considerable importance. These two species of carp are the two 
most important food-fishes in Bengal and they frequently attain a 
weight of over 25 lbs. The fact that the larvae occur in the mus- 
cular tissue and not in the skin, means that they are not removed 
during the ordinary process of cleaning, prior to the fish being 
placed on the table. It is true that if well cooked, the larvae are 
destroyed. Even if not destroyed by cooking we have no informa- 
tion at present as to whether these larval forms mature in the 
human intestine, or not. 
In a previous paper (Rec. Ind. Mus. vol. 1X, part II, June, 
1913) I called attention to the fact that the rare Trematode, 
Gasterodiscus hominis, Lewis and McConnel, has been recorded twice 
from man in Calcutta. It is quite possible that the larval form of 
this Trematode may occur in the skin of fish. In this connection 
it is to be remembered that fish is one of the staple articles of food 
in Bengal. 
Although I have examined several thousands of marine fish 
during an experience of roughly six years on the Ceylon Pearl 
Banks, I have never found either Trematodes or Sporozoa in the 
skin. : 
