HYALOSPHENIA. 81 



pitted, but the siliceous or other scales of more or less 

 definite outline, which characterize the next genus, are 

 altogether wanting. 



1. Hyalosphenia papilio Leidy. 

 (Plate XXIV, figs. 1-4 ; and fig. 79 in text.) 



Difflugia (Catharia) papilio LEIDY in Pr. Acad. Philad. 

 1874, p. 156. 



Hyalosphenia papilio LEIDY in Pr. Acad. Philad. 1875, p. 

 415 ; op. cit. 1876, p. 197 ; and Freshw. Rhiz. N". Amer. 

 (1879), p. 131, t. xxi; HITCHCOCK Synops. Freshw. Rhiz. 

 (1881), p. 18 ; ENTZ in Biol. Centralbl. II (1882), p. 451 ; 

 TARANEK in Sitzber. bohm. Ges. Wiss. 1881 (1882), p. 

 229 ; BLOCHMANN Mikr. Thierw. Susswass. (1886), p. 12 ;. 

 and ed. 2 (1895), p. 15, t. i, f. 13; F. B. CARTER in 

 Amer. M. Micr. Jrn. IX (1888), p. 10; HARVEY in Amer. 

 Natur. XXII (1888), p. 72 ; PENARDHI Mem. Soc. Geneve, 

 XXXI (1890), 2, p. 165, t. vii, ff. 23-35; in Jahrb. 

 nassau. Ver. Naturk. XLIII (1890), p. 71 ; Faune Rhiz. 

 Leman (1902), p. 337, ff. 1-5; and in Pr. R. Soc. 

 Edinb. XXV, 8 (1905), p. 594; GRUBER in Zacharias' 

 Tierw. Susswass. (1891), I, p. 139, f. 16 (6) ; RHDMBLER 

 inZeits. wiss. Zool. LII, 4 (1891), p. 518; CASH in Tr. 

 Manch. Micr. Soc. 1891 (1892), p. 49, t. ii, f. 9; LORD in 

 Tr. Manch. Micr. Soc. 1891 (1892), p. 56; LEVANDER in 

 Acta Soc. Fauna Fenn. XII (1894), 2, p. 20 ; op. cit. XVIII 

 (1900), 6, p. 72 etc.: and XX (1901), 8, p. 8; SCHAUDINN in 

 Deutsch-Ost-Africa, IV, 2 (1897), 19, p. 8; DADAY in Ter- 

 mesz. Fuzetek, XXI (1898), Suppl. pp. 5, 9 ; AVERINTZEV 

 in Trudui S.-Peterb. Obshch. XXX, 1 (1900), p. 239; op. 

 cit. XXXVI (1906), 2, p. 228; in Ber. Susswass. Nat. Ges. 

 St. Petersb. I (1901), p. 211; and in Protok. S.-Peterb. 

 Obshch. XXXI, 7 (1901), p. 323; EYPERTH Naturgesch. 

 mikr. Susswass. ed. 3 (1900), p. 261 ; LAGERHEIM in Forh. 

 Geol. Foren. Stockholm, XXIII (1901), p. 514 etc.; 

 SCHOUTEDEN in Ann. Biol. Lacustre, I, 3 (1906), p. 352; 

 LANDACRE in Pr. Ohio Acad. Sci. IV, 10 (1908), p. 428. 



Test chitinous, transparent, yellowish, plain or with 

 extremely delicate surface-markings or punctulations 

 (visible only under a high power) ; in broad view 

 oblong-oval or pyriform, the crown forming a semi- 

 circle with a minute pore on each side at the broadest 



VOL. II. 6 



