64 BRITISH FRESHWATER RHIZOPODA. 



conjugating confervoid algae and desmids. Assuming 

 it to be a species of Dijjlugia he gave it the specific 

 name of compressa. Penard's more recent researches 

 show that it rightly belongs to his genus Pontigulasia, 

 and it has become familiar under the name of P. 

 bigibbosa Penard ; but we feel bound to revert to 

 Carter's original specific name, notwithstanding the 

 fact that another and quite different form, found on 

 the continent, has recently received from Rhumbler 

 the name of Pontigulasia compressa. Carter's figures 

 in ' Ann. and Mag. Nat. Hist.,' ser. 3, vol. xiii, plate T, 

 place beyond question the identity of Difflugia com- 

 pressa with the Pontigulasia bigibbosa of Penard. 



[Var. flexa var. nov. (Plate XXIII, figs. 6 and 7.) 



Test narrower in proportion to its length, and 

 with a much more oblique aperture than in the type, 

 the neck having a considerable lateral flexure, and the 

 aperture forming an angle of about 45 degrees with 

 the general axis of the test. Surface of test much 

 smoother than in the type. 



Dimensions : Length 140 p ; breadth in front view 

 80 /x, in lateral view 60 JJL ; diameter of aperture 25 /x. 



In Sphagnum-pool, Moel Siabod, N. Wales, at 2500 

 ft., June, 1908 (J. Hopldnson). 



Empty tests only were found, but they differ so much 

 from those of Pontigulasia compressa as hitherto seen 

 that the form appears to merit at least varietal rank ; 

 an opinion evidently held by Mr. Cash, who made 

 the following brief remarks upon it: "bigibbosa ? 

 var." "Mouth oblique (more so than in the type)." 

 " Probably distinct." 



This and all the other rhizopods for which the 

 locality Moel Siabod is given were found in a small 

 sphagnous bog-pool just under the rocky peak over- 

 looking Capel Curig, the source of a rivulet apparently 

 the highest on the mountain.] 



