DIPPLUGIA LUCIDA. 33 



The test of this species differs from tliose of other 

 Difflugise in being evenly compressed, so much so that 

 the two sides, when the test is viewed laterally, are 

 nearly parallel from the crown to the oral aperture. In 

 broad view individuals differ in the degree of contrac- 

 tion anteriorly ; in British examples they are narrower, 

 in proportion to the diameter below the crown, than 

 Penard represents in his figures of continental ex- 

 amples, though in other respects no disparity is notice- 

 able. The test when empty is bluish grey in colour, 

 shining, transparent, and with no adventitious matter 

 adhering except filmy siliceous particles. 



13. Difflugia globulus (Bhrenberg).* 

 (Plate XXI, figs. 5-9 ; and figs. 52-54 and 110 in text.) 



Arcella globulus Bheenbees in Monatsb. Akad. Wiss. 

 Berlin, 1848, p. 379 ; op. cit. 1856, p. 337, t., f. 4 (; ?idem, 

 Mikrogeol. (1854), t. xxxiv, f. ii, 2; t. xxxviii, f. xxi, 9). 



Difflugia proteiformis sub-sp. glohularis Wallich in Ann. 

 Nat. Hist. (3) XIII (1864), p. 241, t. xv, f . 4 /i, ; t. xvi, 

 ff. 1, 2, 17, 21. 



Difflugia glohularis Leidy in Pr. Acad. Pliilad. 1877 (1878), 

 pp. 307, 321. (Non D. glohularis Kheenbeeg in Abb. Akad. 

 Wiss. Berlin, 1871 (1872), p. 253, t. iii, f. 24.) 



Difflugia globulosa (Duj.) Leidy (pars) Freshw. Rhiz. N. 

 Amer. (1879), p. 96, t. xv, ff. 29, 30?; t. xvi, ff. 1-10, 

 21-24; Bdtschli in Bronn's Thier-Reichs, I, 1 (1880), 

 t. iii, f. 1 ; Hitchcock Synops. Freshw. Rhiz. (1881), p. 

 11; Taranek in Sitzber. bohm. Ges. Wiss. 1881 (1882), 

 p. 226; Db Taee in Rep.K York State Mus. XXXV (1884), 

 p. 165; JiCKELi in Zool. Anzeig. VII (1884), p. 449; in 

 Ann. Nat. Hist. (5) XIV (1884), p. 297 ; and in Jrn. R. 

 Micr. Soc. (2) IV (1884), p. 911; Blanc in Bull. Soc. 

 Vaudoise (2) XX (1885), p. 288 ; in Ann. Nat. Hist. (5) 

 XV (1885), p. 427; in Arch. Sci. nat. (3) XXVI (1891), 

 p. 577; op. cit. (3) XXVII (1892), p. 472; and Difflugies 

 Lac Leman (1892), p. 3, t. ii, ff. 7-10, 16-20 ; Blochmann 

 Mikr. Thierw. Siisswass. (1886), p. 12, t. i, f. 18; ed. 2 

 (1895), p. 16, t. i, f. 15 ; FiELDE in Pr. Acad. Philad. 1887, 

 p. 122; FoEEL in Boll. Scient. Ill, an. 9 (1887), p. 90; 

 * [Difflugia glohularis Wallioh : Cash, MS.] 

 VOL. II. 3 



