108 
The difficulties I advert to, as they appear to me, I have 
already tried as succinctly as possible to set forth,! so that I 
need not here recapitulate them. I would only just mention, 
as connected with the question, that, as it would seem to 
me, the more the “ Heliozoan”’ group are studied, the more 
closely do certain representatives of them, at least, appear to 
annex themselves to the marine “ Radiolaria,” but yet, from 
such, however, the transition is not abrupt to others whose 
negative characters would seem, rightly enough, to forbid 
their admission into that Order. Nor is this in itself to be 
wondered at. In all forms of organization the transitions are 
more or less gradual, and, as bearing on the relations of the 
Heliozoa and the Radiolaria, it is interesting to note 
Haeckel’s statement in a recent memoir (one as noble and 
interesting as we yet owe to his busy pen), that the young 
condition of a typical or true “ Radiolarian”’ is morphologi- 
cally that of a “ Heliozoan.”? It is scarcely necessary, of 
course, tg remark, still less to urge, that this is by no means 
a statement that any of the recognised forms which can rank 
only as Heliozoa are but young or progressive states of forms, 
which, in course of individual development, are fated to rise 
to the dignity of Radiolaria. It seems, I think, as if it 
might rather be interpreted as a statement, that a young 
Radiolarian indeed may be, from a morphological point of 
view, but equivalent to a Heliozoan, but whilst the former 
by-and-by puts on additional characteristics, a true member 
of the latter group can rise no higher, but must remain, with 
its fellows, to present us with a continuous supply, as we find 
them, of examples of its kind. 
Before directly passing on to endeavour to give some 
account of the forms which I have tried to portray in the 
accompanying drawings—one at least new, the others, if not 
new, at all events seemingly comparatively rarely encoun- 
tered, and “ little-known,’—I cannot but make use of the 
opptrtunity to reiterate my own view as to the seeming 
constancy with which the freshwater representatives, at 
least, of the Rhizopoda,? maintain their characteristics and 
special identities, and recur, again and again, more or less 
commonly or rarely. I cannot coincide with those who hold 
that their differences are but accidental and casual, being 
simply due to surrounding circumstances; that, because the 
living part in all throughout is essentially but a little mass or 
1 Loe. cit., Vol. X, p. 21. 
2 Haeckel, “ Beitrage zur Plastiden-theorie,” in ‘ Jenaische Zeitschrift fir 
Medicin und Naturwissenschaft.,’? Bd. V, page 530. 
3 T here use the term in a comprehensive significance. 
