576 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
MATERIAL AND METHODS. 
The larvae which form the subjéct of the present 
paper may all be obtained at Port Erin during July; 
but the observations recorded were commenced in 1907 
about the middle of June, and in 1908 were continued 
during the early part of August. 
All the species have been obtained in the bay, for the 
most part just inside the breakwater or further out 
towards the cliffs opposite the Biological Station. Tow- 
nettings were also taken one evening between Aldrick 
Bay and the Calf Island, but the catch contained just the 
same Polychaet larvae as those from within the bay. 
A simple bolting-silk tow-net (mesh 94), usually sunk 
some distance (probably about 3 fathoms) below the 
surface, was used to obtain the plankton which was either 
fixed in the boat or taken up to the laboratory and 
examined immediately in the living condition; none of 
the larvae were reared in the aquarium. Notes and 
rough sketches of the living larvae were made in the 
laboratory, and from these and stained microscopical 
preparations the following descriptiozs and figures have 
been drawn. In some instances use has also been made 
of sections to determine doubtful points. 
Whilst examining the living larvae I endeavoured to 
obtain measurements of their cilia. This was rendered 
extremely difficult both by their great activity and their 
frequently oblique position or curvature. The measure- 
ments given must therefore be regarded as approximate 
only. In the case of cilia projecting obliquely from the 
body, I have endeavoured to ascertain the length of the 
cilia and not the perpendicular distance of their distal 
ends from the body, a measurement that may easily be 
taken to represent their actual length as long as they are 
. 
2 
a 
a 
