NOTES AND MEMORANDA. 
255 
by the parasite, the Cyclops did not seem to suffer much, but moved 
briskly about in the aquarium ; but in specimens where the worm was 
pretty freely grown the orange-red fat drops which usually filled the 
animal had disappeared, and the ovaries had become atrophical 
(the males were not observed to have parasites ; they would on account 
of their small size be destroyed before the worm attained the requi- 
site size.) 
As regards the introduction of the parasites, it must be presumed 
that the eggs of the Tcenia are swallowed by the Copepoda, which 
feed on all kinds of organic matter floating in the water, in whose 
stomach they hatch, and thence migrate through the walls of the 
stomach into the cavity of the body. The eggs must be uncommonly 
small to be taken through the narrow passage between the toothed 
mandibles into the gullet and stomach. 
The worms doubtless become developed into Tasnia in the intes- 
tines of one of the numerous fishes which feed on the small Crustacea 
of the sea, and it appears most probable that this parasite, which has 
chosen such a circumscribed, and for its kind so unusual a domicile, is 
the young of the Tcenia torulosa, which, according to Rudolphi,* 
infest the Cyprinoideas of our fresh-water lakes, although I have not 
succeeded hitherto in finding them.j’ 
On the supposed Badiolarians and Diatomacece of the Coal-measures, 
— Professor W. C. Williamson, F.R.S., called attention, at the Dublin 
Meeting of the British Association, to the Traquarice of Mr. 
Carruthers, found in the lower coal-measures of Lancashire and York- 
shire, with small spherical objects that observer believes to be Radio- 
larians like those still living in existing seas. Professor Williamson 
showed that the radiating projections with which these spheres are 
surrounded were not siliceous spines like those of the Radiolarige, but 
extensions of a continuous membrane which enclosed the entire 
organism, and which therefore could not have the spicular nature 
attributed to them. He then demonstrated that within this external 
membrane is a second inner one, which latter is filled with numerous 
small vegetable cells, like others shown to exist in the interior of fossil 
spores and reproductive cryptogam ous capsules found in the same 
beds as those which furnish the Traquarice. 
These conditions are so different from those existing in any known 
recent species of Radiolarian as to lead Professor Williamson to reject 
the idea of their Radiolarian character ; whilst their close organic 
resemblance to some obviously vegetable conceptacles found in the 
same coal-measures suggested that the Traquarice are also vegetable 
structures. 
The mountain limestone deposits of some British localities contain 
a vast multitude of minute calcareous organisms which Mr. Sollas and 
other observers have regarded as Radiolarians. These structures, 
however, seem to exhibit no satisfactory evidence of being so. In 
the first place these organisms are now calcareous instead of siliceous. 
* ‘ Hist. Nat. Entozoomm,’ ii. p. Ill, and Dujardin, ‘ Helminthes,’ p. 584. 
t ‘ Zoologischer Anzeiger,’ vol. i. p. 74. 
