62 BRITISH FRESHWATEIl RH1ZOPODA. 



vary not only in different individuals but even on the 

 opposite sides of the same test. The row adjoining 

 the aperture is usually formed of similar plates, but 

 the central series often has a larger or smaller central 

 plate with others arranged around it varying in size 

 to suit their positions, but in any case the scales, 

 visible in side view, number four (rarely five) counted 

 in vertical series from the apex to the aperture ; the 

 imbrications of the plates are clearly visible at the 

 margins. 



Usually but few individuals are found in any gather- 

 ing, but occasionally, as at Flitwick, Beds, they may 

 be numerous. The pseudopodia are seldom observed. 

 The neck is never notched as in $. lenta, from which 

 8. fissirostris is also distinguished by its elongate form 

 and the shape and restricted number of the scales. 



3. Sphenoderia macrolepis Leidy. 

 Plate XLIIT, figs. 11-13.) 



Sphenoderia macrolepis 

 LEIDY Freshw. Rhiz. N. Amer. (1879), p. 232, fig. on p. 290 ; Proc. 



Acad. Philad. 1879, p. 163. 



HITCHCOCK Synops. Fresliw. Rhiz. (1881), p. 41. 

 EYFERTH Einfach. Lebensf., ed. 3 (1900), p. 268. 

 PENARD Faune Rhiz. Leinan (1902), p. 577, f. 11, p. 572. 

 AVERINTZEFF in Arch. Protist. VIII (1906), p. 113; in Trudui 



S.-Peterb. Obshch. XXXVI, n (1906), pp. 301-302. 

 SCHOUTEDEN in Ann. Biol. lacustre, I (1906), pp. 369, 370. 

 BROWN in Jrn. Linn. Soc., Zool. XXXII (1911), pp. 83-84, pi. ix, f. 19 ; 



in Ann. Scott. Nat. Hist. 1911, pp. 229, 231 ; in Scott. Natur. 1913, 



p. 208. 

 WAILES & PENARD in Proc. R. Irish Acad. XXXI, LXV (1911), pp. 



19, 52-53, pi. vi, f. 32. 

 WAILES in Scott. Natur. 1912, pp. 61, 64-65 ; in Jrn. Linn. Soc., Zool. 



XXXII (1912), pp. 126, 152. 

 Euglypha macrolepis 



BLOCHMANN Mikr. Thierw. Siisswass. (1886), p. 14; ed. 2 (1895), p. 18. 



Test small, hyaline, oviform, formed of various-sized 

 oval plates and discs ; transverse section oval ; neck 

 conical in side view; aperture linear; nucleus not large, 

 placed posteriorly; plasma clear, colourless, with a vary- 

 ing number of granules ; one contractile vesicle usually 

 present; pseudopodia few, simple, and radiating. 



