NOTES AND MEMORANDA. 7 
cospheres and rhabdospheres live abundantly on the surface, 
especially in warmer seas. If a bucket of water be allowed 
to stand over night with a few pieces of thread in it, on 
examining the threads carefully many examples may usually 
be found attached to them; but Mr. Murray has found an 
unfailing supply of all forms in the stomachs of Salpz. 
What these coccospheres and rhabdospheres are we are not 
yet in a position to say with certainty; but our strong im- 
pression is that they are either alge of a peculiar form, or 
the reproductive gemmules, or the sporangia of some minute 
organism, probably an alga, in which latter case the cocco- 
liths and rhabdoliths might be regarded as representing in 
position and function the “ amphidisci” on the surface of the 
gemmules of Spongilla, or the spiny facets on the zygospores 
of many of the Desmide. There are many forms of cocco- 
liths and rhabdoliths, and many of these are so distinct that 
they evidently indicate different species. Mr. Murray be- 
lieves, however, that only one form is met with on one 
sphere; and that in order to produce the numerous forms 
figured by Haeckel and Oscar Schmidt, all of which, and 
many additional varieties, he has observed, the spheres ‘must 
vary in age and development, or in kind. Their constant 
presence in the surface-net, in surface-water drawn in a 
bucket, and in the stomachs of surface animals, sufficiently 
prove that, like the ooze-forming foraminiferes, the coccoliths 
and thabdoliths, which enter so largely into the composition 
of the recent deep-sea calcareous formations, live on the sur- 
face and at intermediate depths, and sink to the bottom after 
death. Coccospheres and rhabdospheres have a very wide 
but not an unlimited distribution. From the Cape of Good 
Hope they rapidly decreased in number on the surface, and 
at the bottom, we progressed southwards. The proportion of 
their remains in the Globigerina ooze near the Crozets and 
Prince Edward Island was “comparatively small; and to this 
circumstance the extreme clearness and the unusual appear- 
ance of being composed of Globigerinze alone was probably 
mainly due. We found the same kind of ooze nearly free 
from coccoliths and rhabdoliths in what may be considered 
about a corresponding latitude in the north, to the west of 
Farode.—WYyviL_E Tuomson, Joc. cit. 
