X40 MK» G. H. WAILES ON FRESHWATER RHIZOPODA 



111 the Seychelles (fig. 43) it is found without the small covering-plates, 

 but having an admisture, usually 5 to 10 per cent., of circular discs in 

 the composition of the tests. 



It differs from Quadrula symmetricahoth in shape and structure of the test. 



Leidy's illustration is of an individual, length 140 /*, breadth 100 ^, 

 aperture 30 //.. 



Nebela tincta (Leidy), Aiver. 



Hyahspheiiia tincta, Leidy. 

 Nebela hursella, Taranek. 

 Nebela lohemica, Taranek. 



Plentiful in all gatherings of sphagnum, but scarce in mosses. The limits 

 of this species, both as regards size and form, are difficult to define. On the 

 one hand it approaches N. collaris, and on the other N. flabellulum. 



N. TROPICA, sp. nov. (PL 12. figs. 13 & 14.) 



Test of medium size, hyaline, pyriform, compressed ; composed of 

 rectanoukr siliceous plates ; aperture dilated in broad view, with a shallow 

 notch in narrow view. 



Length 74-93 ytt ; breadth 45-GO fi ; aperture 20-30 /* ; thickness 

 30-35 /x. 



Hahitat. Moss. 



Distribution. Borneo ; Seychelles (fig. 44). 



The arrangement of the plates forming the test is generally more regular 

 near the fundus, where they are arranged diagonally, than near the aperture. 

 In the outline of the test there is a close resemblance to JS\ militaris, but the 

 structure and general appearance are very similar to those of iV. scutellata,. 

 a species to which it is undoubtedly closely allied. For comparison with 

 Quadnda si/mmetrica, ^gures of the latter are given on PI. 12. figs. 18, 19, 45. 

 The moss in which this species was first found was collected at Sarawak, 

 Borneo, by J. Brook. 



N. TUBULATA, Broion (3), 

 Leidy, pi. 24. fig. 18 (30). 



This is not uncommon in sphagnum ; the form with a torulose neck is also 

 frequent (45). 



Length 56-78 //- ; breadth 28-48 /z ; aperture 10-15 /a ; length of neck 

 18-32 fi. 



Leidy's fig. 18 measures 80 yu, in length, but fig. 19 of a similar test scales 

 250 /A at the stated magnification of x 100 ; this is probably a mistake for 

 X 350, at which the test would measure 71 yu, in length. 



