60 BRITISH FRESHWATER RHIZOPODA. 
There is some similarity between NV. tubulata and 
small forms of N. barbata, which are occasionally found 
about 80 p in length, especially if these are seen in oil- 
of-cloves or in canada balsam, as in these media the 
fine cils which cover the tests are invisible; but its 
tapering neck and less compression of the test serve 
to distinguish them even if the cils are overlooked. 
5. Nebela scotica Brown. 
(Plate LXI, fig. 17; Pl. LXIII, figs. 3-7.) 
Nebela scotica 
Brown in Jrn. Linn. Soc., Zool. XXXII (1911), pp. 79-80, pl. ix, 
ff. 5-8; in Scott. Natur. 1913, p. 207. 
Nebela dentistoma vay. lagenifo: mis 
PLAYFAIR in Proc. Linn. Soc. N.S. Wales, XLII, 4 (1918), p. 659, 
pl. xxxix, f. 5. 
Test of medium size, grey in colour, pyriform, 
moderately compressed, the short neck terminating in 
a broadly-elliptical aperture; the surface of the test 
usually smooth but occasionally irregular, composed 
of transparent colourless scales of various shapes, 
occasionally imbricated; plasma and pseudopodia 
normal. 
Length 78-82 uw; breadth 57-59 pw; aperture 18-19 p; 
thickness 40 p. 
Habitat.—Sphagnum. 
Enetaxp.— Westmorland (Broun). 
Scot.and.—Ben Ledi, Perthshire (Brown). 
It is questionable if it; would not be more appropriate 
to record this species as a form or variety of N. dentis- 
toma Penard, as in the case of a very similar American 
form, N. dentistoma var. lacustris Wailes,* which is 
140- -200 pe i in length but of similar form and _ propor- 
tions. NV. dentistoma is remarkable for its polymorphic 
tendencies, the test varying in form from elongate- 
ovoid to nearly circular, in this latter case being often 
similar to N. acolla Cash. 
* «Journ. Linn. Soe., Zool.’ vol. xxii, p. 187 (1912). 
