28 BRITISH FRESHWATER EHIZOPODA. 



Var. elegans (Penard). (Plate XX, figs. 2-5 ; and 

 fig. 48 in text.) 



Difflugia acuminata LEIDY (pars) Fresh w. Rliiz. N. Amer. 



p. Ill, t. xiii, ff. 23-26; RHUMBLER (pars) in Zeits. wiss. 



Zool. LII, 4 (1891), t. xxxii, f. 8. 

 Difflugia elegans PENARD (pars) in Mem. Soc. Geneve, XXXI 



'(1890), 2, p. 140, t. iv, if. 7, 8; in Jahrb. nassau. Ver. 



Naturk. XLIII (1890), p. 70; in Arch. Sci. nat. (3), 



XXVI (1891), p. 143; op. cit. (4) VII (1899), p. 251 etc.; 



in Rev. Suisse Zool. VII, 1 (1899), p. 100, t. ix, if. 13-15; 



and Faune Rhiz. Leman (1902), p. 236, ff. 1-7, 9, 11 (p. 



237) ; RHUMBLER (pars) in Zeits. wiss. Zool. LXI, 1 (1895), 



p. 44, t. iv, ff. 9, 11, 16, 19; PROWAZEK (pars) in Arb. 



zool. lust. Wien, XII, 3 (1900), p. 251 etc., t. i, ff . 7, 8 ; 



FOREL Le Leman (1904), III, p. 138; SCHNEIDER in Arch. 



Biontol. II, 1 (1908), p. 58. 

 Difflugia Solowetzkii AVERINTZEV (pars) in Trudui S.-Peterb. 



Obshch. XXXVI (1906), 2, p. 189; SCHODTEDEN (pars), 



in Ann. Biol. Lacustre, I, 3 (1906), pp. 342, 345. 



Test chitinous, transparent, very variable, Avith a 

 rounded, acuminate or irregularly-formed crown, ter- 

 minated by a hollow horn-like tube, which is erect or 

 curved, and sometimes (by no means always) perforated 

 at the apex ; sides more or less curved, and inflated 

 below the crown, frequently unsymmetrical, and 

 constricted to a greater or less degree immediately 

 above the mouth, of which the margin is not recurved; 

 covered with minute elongated or rod-like diatom- 

 shells, some of which are attached by their extremities 

 and stand out at varying angles, rarely with larger 

 Naviculse. The living organism distinctly visible 

 through the scales of the test, showing the cavity to be 

 about three-fourths occupied; the body containing 

 granular matter, and chlorophyllous pellets rather 

 sparingly, and a single comparatively large nucleus. 

 Pseudopodia simple, not numerous, thrust outwards 

 through a mass of loose sandy particles, which nearly 

 always surround the orifice. 



Dimensions: Length 100-1 20 /x. 



