(8) 
Order I. AMCBINA. 
Family 1. Lososa. 
1. Amceba fluida Gruber. 
(Plate LVIII, fig. 1.) 
Ameba fluida 
GRUBER in Zeits. wiss. Zool. XLI, 2 (1884), pp. 219-220, pl. xv, f£. 49. 
PENARD Faune Rhiz. Léman (1902), pp. 42-44, 6 tigs.; Sarcodinés in 
Cat. Invert. Suisse (1905), p. 13. 
Hopxinson in Irish Natur. 1910 (Jan.), p. 2. 
Brown in Naturalist, 1910 (Feb.), p. 91; in Brit. Assoc. Handb. 
Sheffield (1910, Aug.), p. 501. 
Wales in Jrn. Linn. Soc., Zool. XXXII (1912), p. 123. 
Body ovoid+ with rounded outlines, more or less 
yellowish in colour, the expansions of the plasma 
lobular or wave-like; the plasma finely and densely 
granular, the granules being in continual motion both 
vibratory and circulating; nucleus single, colourless, 
containing a granular nucleole and usually several 
vacuoles; one to three contractile vesicles usually 
present. 
Length 50-80 w or more. 
Habitat.—Ponds and aquatic vegetation. 
Eneianp.—W. Yorkshire* ; Derbyshire (Brown). 
Iretanp.—Killough, Co. Wicklow (Hopkinson). 
The constant vibratory movements of the numerous 
granules in the plasma and the circulation of the 
plasma as a whole are striking features in this 
species. Progression takes place by wave-like ex- 
pansions which usually occur in rapid succession. 
The nucleus and the yellowish colour of the plasma 
due to large numbers of minute, coloured grains, are 
characteristic. 
*N., E., and W. Yorkshire signify the North, East, and West Ridings. 
