NEBELA AMEH1CANA. 117 



downwards to the mouth, the lines on each side being in- 

 terrupted only by the slight swelling (as in N. tubulosa) 

 which indicates the position of the lateral pores. In 

 empty tests the appearance is sometimes presented of a 

 distinct line, convex on its lower surface, carried trans- 

 versely across the test and connecting the two pores. 



12. Nebela flabellulum Leidy. 

 (Plate XXVIII, figs. 1-6.) 



Difflugia (Nebela) flabellulum LEIDY in Pr. Acad. Philad. 

 1874, p. 157. 



Nebtla flabellulum LEIDY in Pr. Acad. Philad. 1876, p. 118, 

 ff. 6, 7; op. cit. 1877, p. 264; 1879, p. 162 ; 1880, pp. 333, 

 337; and Freshw. Rhiz. N. Amer. (1879), p. 152, t. xxiii, 

 ff. 8-19; HITCHCOCK Synops. Freshw. Ehiz. (1881), p. 21 ; 

 TARANEK in Abh. bohm. Ges. Wiss. (6) XI (1882), 8, p. 33, 

 t. i, ff. 14-17 ; PENAED (pars) in Mem. Soc. Geneve, XXXI 

 (1890), 2, p. 160, t. vi,ff. 62-66; HARVEY in Amer. Natur. 

 XXII (1888), p. 73 ; LORD in Tr. Manch. Micr. Soc. 1891 

 (1892), p. 56; STENROOS in Acta Soc. Fauna Fenn. XVII 

 (1898), 1, p. 35 etc.; LAGERHEIM in Forh. Geol. Foren. 

 Stockholm, XXIII (1901), p. 515; LEVANDER in Acta Soc. 

 Fauna Fenn. XVIII (1900), 6, p. 33 etc.; and op. cit. XX 

 (1901), 8, p. 9; G. S. WEST in Jrn. Linn. Soc., Zool. 

 XXVIII (1901), p. 322 ; in Ann. Scott. Nat, Hist, 1905, 

 pp. 90, 92; and in Tr. R. Irish Acad. B. 2 (1906), p. 96; 

 BEARDSLEY in Tr. Amer. Micr. Soc. (1902), p. 57 ; MURRAY 

 in Ann. Scott. Nat. Hist. 1907, p. 95. 



Nebela collaris var. flabellulum GREEFF in Sitzber. Ges. Nat. 

 Marburg, 1888, 3, p. Ill; SCHEWIAKOFF in Mem. Acad. 

 Sci. St. Petersb. (7) XLI (1893), 8, p. 98. 



Nebela flabellulum-collaris PENARD Faune Rlnz. Lernan 

 (1902), p. 366. 



Nebela collaris (pars) AVERINTZEV in Trudui S.-Peterb. 

 Obshch. XXXVI (1906), 2, p. 251 ; SCHOUTEDEN (pars) 

 in Ann. Biol. Lacustre, I, 3 (1906), pp. 354, 356. 



Test generally rather smaller than that of Nebela 

 tincta; in broad view expanded laterally and fan- 

 shaped, its breadth iiwariably exceeding the vertical 

 dimension ; much compressed ; the sides abruptly 

 narrowed below into a short cylindrical neck. The 

 body in lateral view compressed into an ellipse, the 



