181 
THIRD REPORT on the COPEPODA of LIVERPOOL 
BAY (the L.M.B.C. DISTRICT). 
By Isaac C. THompson, F.L.S., F.R.M.S. 
With Plate VIII. 
[Read 8th March, 1889.] 
In the two previous Reports* on the marine Copepoda 
of the district fifty species were recorded. The second of 
these reports was drawn up at the close of 1887, and it is 
now most satisfactory to be able to record thirty-three 
additions since that time, of which five are new to British 
seas. As before, the majority have been taken by tow-net 
in the open sea, or by hand-net from the rocky shore 
pools seldom touched by ordinary tides. 
A considerable number of the additional species we have 
lately obtained from sand and mud brought up by the 
dredge, and taken at low water in tidal pools, &&. Want 
of success in this direction has probably arisen previously 
from washing the material in sieves which allowed many 
of the very minute forms to escape with the water. 
The method latterly adopted has been to place the solid 
material direct into a very fine muslin bag, or into the 
finest meshed tow-net itself. Tied at the top, the bag 
is placed in a running stream of water, by which means 
all the soluble portion and the very finely suspended mud 
particles constituting the bulk of the mass are washed out. 
On examining the residue in a saucer of water, numbers of 
Copepoda are found floating upon the surface, which 
washed in the ordinary way would have been lost, and 
* See ‘‘Fauna of Liverpool Bay,” &c., vol. i., p. 201, 1886; and ‘‘ Proc. 
L’pool Biol. Soc.,” vol. ii., p. 63, 1888. 
