64 BRITISH FRESHWATER RHIZOPODA. 
Genus 2. DACTYLOSPHARIUM Hertwig & 
Lesser, 1874. 
Amba (pars) Enxrensere in Abh. K,. Akad. Wiss. Berlin, 
1830 (1832), p. 39, and Infus. (1838), p. 128. 
Dactylospherium Hertwie & Lesser in Arch. f. Mikr. 
Anat. X (1874), Suppl., p. 54. 
Body ameceboid; distinguished from Ameba by the 
possession, during the quiescent phase, of rigid or but 
slightly flexuose pseudopodia, which radiate irregularly 
from the sub-globular body-mass, and are variable in 
number and length. Pseudopodal movements slow, 
the pseudopodia often immobile for long periods ; 
endoplasm as in Ameba, generally colourless or only 
slightly tinged with green, except in D. polypodium. 
The latter, in the density and colour of its endoplasm, 
approaches J/astigameba. 
The rigid and frequently elongated and pointed 
pseudopodia (in the resting-phase) mainly characterize 
this genus. D. vadiosum is truly amoeboid in the 
active phase. 
1. Dactylospherium radiosum (Ehrenb.) Biitschli. 
(Plate IIT, figs. 8-11; Pl. LV. figs. 6-11.) 
Ameba vradiosa Hurensure in Abh. K, Akad. Wiss. Berlin, 
1830 (1832), p. 39; op. cit. 1831 (1832), p. 80; and Infus. 
(1838), p. 128, t. viii, f. xiii; Prircparp, Nat. Hist. Ani- 
male. (1834), p. 38; Hist. Infus. (1842), p. 166, t. ii, f. 88; 
new ed. (1852), p. 202, t. 1i, f. 88; and ed. 4 (1861), p. 549, 
t. xxil, ff. 1-3; Perry Kenntn. kleinst. Lebensf. (1852), 
p- 188; Cotnin Proc. Essex Inst. I (1853), p. 45; Scumarpa 
Grundz. Zool. I (1853), p. 26, f. 15; Averpacn in Zeits. 
f. wiss. Zool. VIT (1856), p. 400, t. xxi; Pick in Verh. 
Vereins Wien, VII (1857), p.36; Carrenrmr Foram. (1862, 
Ray Soc.), p. 24, t.1, £. 15; t.iv, ff. 6,7; Carus Handb. 
Zool. IT ae p. 591; Wauiich in Ann. Nat. Hist. (3) 
XI (1863), 443; Wintramson in Pop. Sci. Rev. \ 
(1866), p. 197, t. xiii, ff. 14-16; Czmrny in Arch. f. 
