116 BRITISH FRESHWATER RHIZOPODA. 



its side) descending from the arched crown, each in 

 a straight line, to the corners of the contracted mouth, 



O 7 



which is slightly convex. A pore on each side of the 

 test, about one-third of the distance upwards from the 

 mouth, often marked by a slight prominence. Sub- 

 stance of the test chitinous, with a surfacing of round 

 or angular transparent plates touching at their edges. 

 The test in narrow lateral view slightly inflated above 

 the crown sometimes tapering to a blunt apex and 

 the lower part produced into a narrow neck, which 

 is terminated by the notched mouth. Plasma often 

 crowded with yellowish - green corpuscles, refringent 

 globules and granular matter nearly obscuring the 

 nucleus ; the pseudopodia few in number, simple. 



u 



FIG. 96. Nebela americana ; broad and narrow views. Tan-y-bwlch, 

 N. Wales, x 220. 



Dimensions: Length 1 60-175 /x; breadth 65-75 /u,; 

 at mouth 30-35 /a. 



In moist Sphagnum, Dunham Marsh, 1903; near 

 Towyn and at Tan-y-Bwlch, N. Wales. Loch Ness, 

 Scotland (J. Murray}. 



This species has been regarded by some authors as 

 identical with N. barbata Leidy, but the two are quite 

 distinct. N. barbata usually has much the smaller test ; 

 it has a long and slender neck, and is altogether much 

 more delicate than N. americana. The latter has a 

 brownish test, with a surfacing of circular or poly- 

 gonal plates; the sides are straight from the crown 



