FRESHWATER RHIZOPODS AND HELIOZOA. 311 
was homogeneous and very refractive. The endoplasm was 
dark-coloured and crowded with small granules; it also con- 
tained a well-marked nucleus and one contractile vacuole. 
The genus Dactylospherium appears to be sufficiently well 
marked off from Amaba. The actual body of the animal is not 
strictly amcebiform, but always more or less spherical, sending 
out numbers of long, comparatively thin, attenuated pseudo- 
podia. From what I have seen of these animals, I consider 
‘that Dactylospheria exhibit less active movements than Amabe. 
Some of the mountain forms of D. radiosum keep the same 
pseudopodia protruded to a variable extent for hours at a time. 
Fam. RETICULOSA. 
Gen. GymMNnopPHeys, Cienk. 
8. Gymnopurys comEtA, Cienkowski, in Archiv fur mikr. 
Anat. 1876, xii. p. 31, £.255; Blochmann, Die mikroskop. Thier- 
welt des Stisswass., 1. Protozoa, Hamburg, 1895, p. 14, t. i. £. 9. 
Near Brigg, Lincolnshire. (PI. 28. fig. 3.) From this locality 
several specimens of an animal were obtained which may, per- 
haps, be Cienkowski's Gymnophrys cometa. The body was 
. somewhat small, being about 25 p» in length and 18 uw in breadth, 
and some of them were distinctly constricted in the middle as 
if undergoing division. The pseudopodia varied in number from 
three to five at either end of the body, and sometimes reached 
a length of 100 u. They were delicate and hyaline, frequently 
much branched, and occasionally anastomosed with one another. 
The branches arose suddenly at a considerable angle from the 
main pseudopodial filament and exhibited a very rigid appearance. 
Small granules moved slowly along the pseudopodia, generally 
in groups. 
Contractile vacuoles were entirely absent; this character and 
the peculiar nature of the rigidly-branched pseudopodia easily 
distinguishing it from Biomywa vagans, Leidy, a Rhizopod. with 
which it possesses much affinity. 
No nucleus could be detected in any of the individuals. 
Archer (in Qu. Jour. Micr. Sci. 1877, xvu. p. 349) states 
that Cienkowski’s species reminds him of “a portion of the mass 
of a Gromia become isolated and detached by some readily 
conceivable force, having wandered too far from the head- 
