HYALOSPHENIA 1NCONSPICUA. 85 



Very minute ; test very thin, of a reddish-brown 

 colour, in front view with an almost circular outline, 

 the basal portion being slightly protracted to form a 

 short neck, the mouth small and truncate ; in side 

 view ovate-elliptical in form, with a notched mouth. 

 Plasm occupying only about half the cavity of the 

 shell, with a small nucleus and one short pseudo- 

 podium ; contractile vacuoles not observed. 



Dimensions : Length 14' 5-1 7 //- ; breadth 1 2*5-1 6 /x ; 

 breadth of mouth 6 '5-7 '7 /x. 



Lough Gartan, Co. Donegal, Ireland (West}. 



This minute Hyalosphenia, the author (whose des- 

 cription we quote) says, is considerably smaller than 

 any other known species. It was observed in quan- 

 tity from the above-mentioned locality in May, 190J. 

 The almost circular outline of the shell, and its 

 reddish-brown colour, are characteristic. The animals 

 were very sluggish and only protruded one small 

 pseudopodium. 



4. Hyalosphenia minuta Cash. 

 (Plate XXIV, figs. 5-11.) 



Hyalo*phenia minuta CASH in Tr. Manch. Micr. Soc. 1891 

 (1892), p. 49, t. ii, ff. 3, 4; AVEKINTZEV in Trudui S.-Peterb. 

 Obshch. XXXVI (1906), 2, p. 230; SCHOUTEDEN in Ann. 

 Biol. Lacustre, I, 3 (1906), pp. 351, 352. 



Test small, pellucid, composed of thin chitinous 

 membrane ; in front view ovoid, from the arched 

 crown tapering evenly to the truncated mouth, which 

 is rounded at the corners ; strongly compressed ; the 

 mouth, in narrow lateral view, forming a slight notch. 

 Plasma colourless, attached to the test usually by 

 six or eight attenuated filaments ; nucleus distinct, 

 normally situated ; the pseudopodia varying in number 

 and form, sometimes represented by a single lobe, 

 which is Ungulate and nearly as long as the test, 

 extending outwards, and (when the test is lying on 

 its side) used Amoeba-like as a means of locomotion. 



