AN ICHTHYOBDELLID PARASITIC ON SAND WHITING. 15 
The ducts of the larger glands have a diameter of 8 fi, the 
smaller 6 ^ . 
Salivary Glands. 
The salivary glands, as shown in Text-fig. 4 (S. gl.) are 
placed between the upper level of the eighth, and the lower 
level of the tenth nerve ganglion. On either side of the pro- 
boscis there are about five or six giant-cells and a number of 
smaller ones. The large cells have a diameter of about 120 /u, 
and other cells range in size from that down to 20^. 
Their ducts curve at right angles to the body of the cell and 
enter the base of the proboscis. The character of these cells 
and their relatively huge size is shown in Text-fig. 5. The 
position of the nucleus, which is next to the secretion space 
is also shown. 
The C(elomic System. 
We owe to Johansson (1898) and to Selensky (1906) our 
main knowledge of the coelomic system of the Ichthyobdellids 
other than Pontobdella, Br anchellion, and Ozo- 
branch us. The former in 1896 pointed out the great value 
of the knowledge of this system in systematic work, giving 
a number of examples of the chief features in different 
Ichthyobdellids. This leech, while possessing the main 
features of the coelomic system as described for Piscicola 
and Callobdella, diverges widely in certain respects. This 
divergence is most marked in that part which corresponds to 
the contractile vesicles of Piscicola and Callobdella. 
In Austrobdella, in place of a lateral row of such vesicles, 
there is a continuous contractile lacuna. This lacuna occupies 
the position of the contractile vesicles, as described for allied 
genera, lying laterally just beneath the skin outside the 
muscle layer. On either side it extends from the level of 
the proboscis to the level of the anus, but is contractile only 
in the region of the testes and the thick-walled intestine. 
This genus differs also in wanting altogether the lateral 
