q ' \ 
v4 : 73 
c "moyen desquels l’animal nage librement ou marche 4 la surface des 
_ Hydras.” Saville Kent, in his ‘Manual of the Infusoria,’ p. 646, 
retains the name of TZrichodina pediculus, and, under habitat, 
distinctly classes it as an ectoparasite, referring also to a new 
habitat, on the branchial appendages of larve of Ziriton cristatus. 
% _ This T am able to confirm, having found them this year in the 
same place on larve of Triton. These Trichodina, which are 
] ectoparasitic on the branchiwe of the larva of Zriton, retain their 
_ affinity for Hydra vulgaris, as can be proved by taking some from 
"a larva of Triton whose branchie are infested with them, and 
ss placing them in a watchglass with Hydra, when they will be seen 
rm to attach themselves by their acetabulum to the surface of the 
tentacles of the Hydre. 
I have searched carefully to discover if these Zrichadina are 
ectoparasitic on either the adult triton or newt, but have been 
unsuccessful, although I have captured both in company with 
lary, whose branchix have been infested with them. 
r In order to trace the origin of the Zrichodina which, as I have 
_ said, I found accidentally, I determined in March otf the present 
year to investigate the matter systematically, and accordingly 
_ [killed a male specimen of Triton eristatus with chloroform, washed 
it with warm water with a camel’s hair brush, opened it ventrally, 
and extracted the viscera. These were placed’ in a watchglass with 
‘a ‘distilled water, when numbers of Zrichodina were obser ved with a 
Lin. objective in the fluid; some were taken up with a pipette, 
placed on a glass plate, covered with a cover-glass, and carefully 
compared with the figures of 7. pediculus in Saville Kent’s ‘ Infu- 
 soria,’ which they were found closely toresemble. A female Zriton 
_ was next taken, and subjected to the same process, but proved a 
failure. .A male smooth water-newt was treated in the same way, 
and yielded an abundant supply; but a female newt from the 
same source was barren of results. These preliminary observations 
_ furnished sufficient evidence that the Zrichodina did exist in the 
_ viscera as endoparasites, and I may say that great caution was 
ercised in regard to the cleanliness of the troughs, pipettes, and 
issecting instruments that were used. 
i On the 18th June I captured some newts, and entered upon 
a still more thorough investigation of the subject. 
A small newt was killed with chloroform, washed in warm 
water, afterwards in distilled water, and then placed in an oblong 
glass trough. The lower jaw was removed, and the ventral side 
opened from thorax to anus—a slit being made on cither side to 
allow the dermis to be thrown back, and thus expose the whole ot 
he viscerz. The heart, lungs, and liver, with the gall-bladder, 
re detached and placed on glass plates and covered with small 
ell-glasses. Each was separately examined, at first dry as an 
opaque object, and afterwards immersed in sterilized water and 
