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Haswett—A Monograph of the Temnocephacee. 
TI1.—Disrrisution, Foop, Movements, &c. 
Members of this family have been found in South America, both in Chili (Gay) 
and Brazil (Jhering), in Australia and Tasmania (Haswell), in New Zealand (Wood- 
Mason), in Sumatra, Java, and Celebes (M. Weber), in the Philippines (Semper), in 
Madagascar (Vayssiére) and in North-Eastern India (Wood-Mason). The Chilan 
form was found on the surface of a species of Aeg/ea, the Australian and Tasmanian 
species on fresh-water crayfishes of the genus Astacopsis, the New Zealand species 
on fresh-water crayfishes of the genus Paranephrops. In the Philippines, Java, 
Sumatra, and Celebes, they oceur on species of Zedphusa. The Indian form was 
found by Wood-Mason in bottles containing spirit-specimens of fishes to which they 
may originally have been attached. One Brazilian species was found on the shell of 
a fresh-water tortoise; the other was found as noted above, by Jhering in the branchial 
cavity of a species of Ampullaria. Craspedella Spenceri inhabits the branchial cavities 
of Astacopsis bicarinatus. 
All, with the exception of the last two, live under ordinary circumstances on the 
outer surface of the animal which they select as their host.* Each species seems to 
be quite constant, so far as our knowledge at present extends, in its relation to a 
particular animal ; and it very rarely happens that a Zemnocephala is to be found 
under natural conditions not attached to its host.t But those forms with which 
I have had the opportunity of experimenting are able to live for a very long time— 
it might be almost said indefinitely—after removal from the surface of their host ; and 
Max Weber made the same observation with regard to his 7. Senzperz. 
When undisturbed the Zemnocephal@ (and the same holds good of Crasfedella ), 
adhering by means of their sucker, either remain with the tentacles more or less 
contracted and the ventral surface in close contact with the surface to which the 
sucker is attached, or the body is raised and the tentacles stretched out widely. 
They move along very much after the fashion of a leech, the place of an anterior 
sucker being taken by the tentacles; and they show an amount of alertness and 
sensitiveness not usual among members of their class.{ When an attempt is made to 
* Temnocephala Engei sometimes occurs in the branchial chambers ; and 7’. Dendy? is very frequently found in the 
same position. 
+ Chilton has given an account (Trans. N.Z. Institute, Vol. XXI. p. 252) of his having kept specimens of 7. Vore- 
zealandie alive for months detached from their hosts; and he has informed me that he has found specimens of the same 
species attached to boulders in a New Zealand stream. 
; FE Sphyranura Osleri, as described by Wright and Macallum, appears to be the only Trematode that approaches 
Temnocephala in this respect. 
A remarkable phenomenon is sometimes to be observed when Temnocephalw are placed in very shallow water in a 
vessel. With the sucker adhering to the bottom, one of them is occasionally observed to stretch out the tentacles and 
apply their ventral adhesive faces to the surface of the water, and thus, using the tension of the surface layer as a point 
@appui, the body is drawn up to the surface of the water and the sucker applied to the latter, the animal ‘‘ looping 
along as if on the surface of a solid body. 
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