74 BRITISH FRESHWATER RHIZOPODA. 
the latter usually containing large quantities of ex- 
traneous matter and miscellaneous food particles, and 
always numerous clear corpuscles (the glanzkdrper of 
German naturalists) regarded by the earlier observers 
as zoospores, but more recently proved to be albuminoid, 
and probably a source of nourishment to the symbiotic 
bacteria with which the body of the organism is 
charged.* Nuclei in some species very numerous and 
minute ; in others of the ordinary type, and fewer; 
contractile vacuole absent, its place being apparently 
taken by numerous small watery-looking vacuoles dis- 
persed through the endoplasm. Locomotion effected 
by broad lobular or wave-like expansions of the frontal 
ectoplasm, or by pseudopodia originating on any part 
of the surface, the posterior extremity during active 
movement appearing rounded, and being furnished 
with short sub-persistent hyaline pseudopodia, or with 
a spherical lobe of granular structure (less dense than 
the substance of the body), the surface of which is 
covered with villous processes. 
1. Pelomyxa palustris Gruerr. 
(Plate VII, figs. 1-3.) 
Pelomyea palustris Greerr in Arch. f. mikr. Anat. X (1874), 
p. 51, tt. ii-v; F. E. Scrutze in Arch. f. mikr. Anat, XI 
(1875), p. 342, t. xix, ff. 6-8; Gasrren in Morph. Jahrb. I 
(1876), p. 541; Atnman in Journ. Linn. Soc., Zool. ATI 
(1877), p. 271, f. 5; Arcumr in Q. J. Mier. Sei- XVIT, 
ns. (1877), p. 337, t. xxi, ff. 10-15+; EneGrtmann in 
Arch. ges. Physiol. XIX (1879), p. 1; Bivscuii in Bronn’s 
Thier-Reichs, I, 1 (1880), t. 1i, f. 1; Mikros. Schaume 
(1892), p. 216; and (Engl. transl.) Micros. Foams (189-4), 
p- 116; Kororyurr in Arch. Zool. expér. VIII (1880), 
p. 476, t. xxxvi, ff. 6-23 ; Lapnam in Amer. Journ. Micr. V 
(1880), pp. 165, 197 ; Lanrssan Traité Zool., Prot. (1882), 
p. 44, ff. 82, 83; Ray Lanxesrer in Encycl. Brit. ed. 9, 
XIX (1885), p. 842, f. iv, 5,6; Berruonp Stud. Protopl.- 
mech, (1886), p. 109, t. ui, f. 6; Buochmann Mikr. Thierw. 
* Mrs. L. J. Veley, in ‘ Journ. Linnean Soc.,’ Zool., vol. xxix, pp. 875-386. 
+ As P. lacustris in Zool. Ree. for 1877, Prot. p. 4. 
