1915.] T. SOUTHWELL : Indian Parasites of Fish. 323 
(8) Argulus foliaceus, Linnaeus, from the skin of Labeo 
rohita (Rohu). 
(Plate xxvili, figs. 16-18), 
Agricultural Farm tank, Siripur, Bihar, India. August 20, 
1913. 
During the year 1913 I was engaged making observations with 
reference to the breeding habits of Indian Carp. For this purpose 
three tanks were dug in the Agricultural Farm at Siripur. The 
measurements of the three tanks were the same, namely, 50 ft. in 
length, 37 ft. in breadth and 7 ft. in depth. 
These tanks were situated in a line at right-angles with, and 
very close to, a neighbouring stream, from which they received 
water. 
In addition, it was found that a small spring of water existed 
in the middle tank. The tanks were only separated from each 
other by a narrow bund and they were in connection with each 
other by means of a pipe running through each bund near the 
surface. The tank which we will consider as No. 1 was situated 
nearest to the stream, from which it was distant only about three 
or four yards. 
About eighteen mature specimens of Labeo rohita, both males 
and females, were placed in these three tanks during the latter part 
of July. It was found that large numbers of frogs entered the 
tank nearest to the river. In order to exclude frogs from this 
tank a matted fence was erected all round it. About the middle 
of August, Mr. Mackenzie, the Superintendent of the Agricultural 
Farm, noticed that the fish became sluggish and floated on the top 
of the water. On examining one or two it was found that they 
were covered with external parasites. These were preserved in 
spirit and forwarded to me. The steps taken by the Farm 
Superintendent to remedy the disease were as follows:—First, 
all the fish were captured and scraped as clean as possible. 
The fence matting was then removed giving free access to frogs, 
etc. Lastly, an upright bamboo was erected in the centre of the 
pond. The Farm Superintendent, whose observations and _ state- 
ments are thoroughly reliable, states that the fish proceeded forth- 
with to rub themselves against this bamboo. There were no 
deaths. 
About the end of September all the fish were captured and 
killed and were then found to be perfectly clean; not a single 
parasite was found. The fish present in the second and third 
tank were not affected. I have since ascertained that extensive 
deaths amongst carp in tanks due to “‘ external parasites ’’ have 
occurred, within the last four years, in the districts of Mymensingh 
and Murshidabad, and I have no doubt that the parasite causing 
these diseases was identical with the one obtained from Siripur. 
The forms examined by me are undoubtedly Argulus foltaceus, 
Linn., and have been recorded as external skin and gill parasites 
