132 MK. G. H. WAILES ON FRESHWATER RHIZOPODA 



Genus DiFFLUGiA, Lederc. 



This genus is well represented both in species and numbers o£ individuals ; 

 one new species, D. Leidyi, is recorded. 



DiFFLUGIA ARCULA, Leichj. 



Leidy, pi. 15. figs. 34-37 ; pi. 16. figs. 30, 31 (30). 



This species, which is in an anomalous position among the Diffiugke, has 

 been removed by Penard to the genus Trigonopyxis, gen. nov. ; in future it 

 should be known as T. arcula (Leidy), Penard (Rev. Suisse Zool. 1912). 



It is abundant in sphagnum and damp mosses. 



Diameter 70-140 fi. 



D. BACILLARIARUM, FertlJ. Var. ELEGANS i^Fen.), Cash (10). 



D. acuminata pars, Leidy, pi. 13. tigs. 23-26 (30). 



On PI. 12. figs. 2 & o is shown a form which is abundant at Lakehurst. 

 The test is almost entirely composed of diatom frustnles; in broad view it is 

 two-horned, in narrow side view it appears normal. 



Length 110-130 yu.; breadth 95-105 jjl ; aperture about 35 jx. 



D. Leidyi, sp. nov. (PL 12. figs. 4 & 5.) 

 Leidy, pi. 16. fig. 36 (30). 



Test of medium size, composed of siliceous particles with an admixture of 

 vegetable materials and sometimes of diatoms, circular or subcircular in 

 transverse section : the fundus furnished with two (rarely three) horns 

 arranged symmetrically in one plane ; aperture circular, bordered by small 

 siliceous grains. Plasma and pseudopodia normal. 



Length, not including horns, 100-110 /x ; breadth of body 78-80 fx ; neck 

 35-40 /i in diameter ; horns 30-40 [jl in length. 



Habitat. Submerged sphagnum. 



Distributiofi. New Jersey. 



Leidy (30) illustrates a test of typical form, the only one he observed ; at 

 Lakehurst it is not very rare. 



D. OBLONGA var. CORNUTA, Leidy. 

 Leidy, pi. 12. figs. 17, 18 (30). 



An individual of this variety found at Lakehurst measured : length (in- 

 cluding horn) 240 /A, breadth 120 /x, aperture 32 /x, with a single horn 50 yu 

 in leno'th. Leidy's fig. 18 represents it very accurately, with the exception 

 of the horn, which is smaller than on the Lakehurst specimen. 



