6 
CHARLES BADHAM. 
Distance from oral sucker to male opening 1’26 mm. 
Oiameter of neck at base of oral sicker . *6 mm. 
Breadth of clitellum ..... *95 mm. 
All these measurements are taken from leeches killed by 
means of boiling corrosive acetic solution while in a quiescent 
condition. 
In describing Platybdella micliaelseni, Johansson 
(1911) states that the larger of two specimens secured was 
6*9 mm. long. He found in this specimen that the testes were 
ripe but the ovaries slightly developed, despite the presence 
of spermatozoa. He therefore considers that this species 
would not attain a much greater size. However, if my ob- 
servations on the growth of Austrobdella are found to 
be generally applicable to marine leeches, the species he 
describes might grow to nearly twice the length given. 
Coloration. 
The transparent nature of the body of Austrobdella 
allows the beautiful pigmentation to be clearly seen. The 
drawing (PI. 1, fig. 1) is a careful representation in black 
and white of a living specimen, viewed from the ventral 
surface, as seen by transmitted light. 
The specimen depicted is a young extended form in which 
neither the clitellar region nor the lateral parts of the main 
body region are as well developed as usual. This individual was 
made use of owing to its having retained its colour in captivity 
better than its fellows. 
On the ventral surface most of the pigment cells are seen 
to be wrapped round what appears to be a tube. These cells, 
which are reddish-brown in colour, are in the walls of the 
ventral lacuna ; their stellate nature is well represented. 
Similar pigment cells are seen in relation to the ejaculatory 
canals ; these are here, as in most specimens, rendered con- 
spicuous by their dark colour. 
As well as the reddish-brown pigment cells mentioned, a 
smaller number of cells of varying shades of purple are 
