98 Macteay Menmoriat VouuMe. 
remove them from the surface to which they are clinging, they are able, by flattening 
themselves down, and exercising all the adhesive power of the sucker and tentacles, 
to resist a considerable amount of force. If forcibly separated from their host and 
allowed to fall towards the bottom of the water, they twist and writhe themselves 
about during their passage downwards, so that they often succeed in laying hold of 
some prominent part of their host’s body and reinstating themselves on its surface. 
As regards the nature of their food, the Temmnocephale differ widely from the 
Trematodes. For the most part they live on small Lxtomostraca and Insect-larve, 
as well as Rotifers, all of which they swallow whole. The prey is seized and thrust 
into the mouth by means of the tentacles. Sometimes the animal is found in the act 
of making a vain endeavour to swallow an Entomostracan nearly as long as itself. 
Whole small animals of such sorts have been found by myself in the intestine of 
T. fasciata, T. minor, T. Dendyi, T. quadricornis, and 7. Nove-zealandie, and by 
Max Weber in 7. Sempert, sometimes accompanied by numerous diatoms and 
unicellular alge. In 7. Dendy? I have in one instance found an entire and quite 
unaltered smaller individual in the alimentary canal of a larger one, and in several 
instances in 7. Nove-zealandie I have found the chitinous parts (cirrus and vaginal 
teeth) of one in the intestine of another, the soft parts having apparently been 
digested. But in some specimens of 7. fasczata I have observed that, when the 
crayfish host carried eggs, the alimentary canal was full of red matter resembling the 
yolk, and though it is unlikely that the Trematodes are able to break into the 
eggs (which are far too large for them to swallow whole), yet it would seem as if 
they swallowed the contents of such of them as became accidentally bruised. In 
the case of 7. comes the intestine either contained a reddish granular matter of this 
kind, or a quantity of mud with sand-grains, diatom-valves, etc., and the remains of 
Arthropods were never observed. 
In Craspedella Spencert 1 have only found various unicellular organisms ; in four 
or five instances a number of large green unicellular organisms, which could not be 
identified, but which looked like Euglene. Craspedella is not adapted, owing to the 
absence of the muscular pharynx, to preying on the relatively large living animals 
that form the food of Zemnocephala. 
IT V.—THE INTEGUMENT. 
The most noteworthy feature of the integument in 7emnocephala is the presence, 
in the adult state, in two species at least, of a coating of vibratile cilia. It is quite 
possible—though it does not seem likely—that a careful re-examination of some of 
