312 Records of the Indian Museum. [VoL. XI, 
impossible that certain of these parasites may mature in the 
human intestine. 
The ‘“‘pox’’ recorded from Rasbora daniconius (Bengali 
‘“dankona”’) may become a very fatal disease when occurring in 
limited water-areas such as tanks. 
The parasite from the abdomen of Diagramma crassispinum 
(a fish somewhat like the one known in Bengal as Khora Bhekti) 
is not of any commercial importance. 
An epidemic of goitre amongst the trout at Naini Tal is of a 
serious nature, and if not kept in check will interfere greatly with 
the successful cultivation of this species. 
A case of Glaucoma of the eye in a marine fish recorded in 
this paper is of pathological interest only. 
(1) A skin disease found on Rasbora daniconius. 
(Plate xxvi, fig. 3). 
Four specimens were collected by Capt. R. B. Seymour 
Sewell, B.A., I.M.S., from a stream near Katiwan, Mirzapore 
(U. P.), India. 
In all, six cysts were found on the four fish in question. 
They were situated immediately below the scales, in the epidermis, 
and were milky-white, soft, flattened, and roughly oval in shape. 
The largest measured 1°t mm. No pigment was present. 
Preparations of the contents of these cysts showed that they 
contained Myxosporidia, or parasitic protozoa. The order 
Myxosporidia, Butschli, contains a series of parasites which occur 
in both fresh water and marine fish. They are usually found 
beneath the skin, as small wart-like nodules near the fins and on 
the gills. The parasite causing the well-known silkworm disease 
(Glugea bombycis) is closely related to the parasite recorded in the 
present paper. Representatives of the Myxosporidia have also 
been found in the urinary bladder and gall bladder of fishes, and 
they are also recorded as occurring in Crustacea, frogs, and croco- 
diles. At the present time over 60 species of fish are known to 
harbour parasites included in the order Myxosporidia and about 
50 distinct species of parasites are recognized. In Europe 
epidemics amongst fish have frequently been traced to the pre- 
sence of such parasites, although it appears that the mortality is 
not directly due to their presence, but to the presence of bacilli 
which develop within the cysts and give rise to ulcerations, which, 
discharging, not only kill the fish, but spread the disease. 
Our parasites belong to the family Myxobolidae, Thelohan. 
The characters of this family are as follows :— 
Spores with one or two polar capsules and with a peculiar 
iodinophilous vacuole in the sporoplasm (Minchin). 
The genus Myxobolus, Butschli, 1882, to which our specimens 
belong, are characterized by the presence of one or two polar 
capsules and by the absence from the spore-membrane of a tail- 
like process. Minchin (Lankester’s Zoology, Part I, London 1903, 
