NUCLEARIA DELICATULA. 11] 
the genera Nuclearia and Heterophrys. Archer (loc. 
eit.) described Heterophrys myriapoda, upon which he 
founded the genus, as a Heliozoon. His figures accord 
so closely with undoubted examples of H. varians 
in the heliozoon-like phase, that one is almost forced 
to the conclusion that Heterophirys myrtapoda Archer, 
H. variuns Schulze, and Heliophrys variabilis Greeff, 
are separate phases of a single species, which must be 
regarded as identical with Nuclearia delicatula. 
The habit of what may be assumed to have been a 
young state of the species under notice (Pl. XII, 
figs. 7, 8), was extremely puzzling. The pseudopodia 
were mobile, sometimes straight, clustered at various 
angles of the body, or scattered, curved, and whip- 
like, changing their position repeatedly and apparently 
performing the function of tentacles. The movements 
of these young, comparatively-transparent individuals, 
reminded one of Vampyrella lateritia m its most active 
state, but in other respects they differed widely from 
that species. 
In one form of the species (Pl. XII, figs. 1, 2) there 
was an absence of the external envelope, but the 
movements of the organism were normal. In the 
heliozoon phase the spherical body gave off a large 
number of short radiating pseudopodia, composed of 
clear ectoplasm, with three or four more-conspicuous 
ones at various points. Only when in active movement 
could the affinities of this organism be arrived at. 
If further investigation should establish the identity 
of Heterophrys myriapoda Arch., with Nuclearia deli- 
catula Cienk., Archer’s genus Heterophrys should, it 
seems to us, be dropped. West, however (‘Journ. 
Linn. Soc.,’ Zool., vol. xxvii, p. 537), describes under 
the name of Heterophrys radiata, a small, dark-grey 
heliozoon, possessing an outer colourless gelatinous 
coat, almost as thick as the diameter of the body, with 
a finely-fimbriated outer surface, and numerous long 
and delicate pseudopodia. It has no affinity with 
Nuclearia. 
