70 INDEX. 
PAGE 
CoNCHULINA . i . 18 
Corycia Duj. 24, 25 
dujardini Gagl. . . 25 
jlava Pen. . 25, 26 
radiata Brown. . 27 
Cryptodifflugia Pen. 50, 53 
“compressa Pen. 51, 52 
eboracensis Wailes 51, 53 
oviformis Pen. 50, 51, 52 
sacculus Pen. 51, 54 
Cucurbitella Pen. j . AT 
mespiliformis Pen. . 48 
Cyclotella Kuetz. 18, 20, 21 
operculata Kuetz. . 19 
Cymbella Agardh 17, 20 
operculata Agardh 18, 20 
Diaphoropodon mobile Arch.. 6 
Difflugia Leidy 4, 6, 47 (syn.), 48 
acuminata Ehrenb. . ob 
var. curvata Cash 6 
amphora Ehrenb. . 39 
amphora Leidy  . . 40 
amphora Pen. ‘ 39 
amphoralis Hopk. . 40 
cassis Wallich . . 44 
constricta (Ehrenb.) Leidy 
4, 42 (syn.), 43, 44, 46 
vur. spinifera Playf. . 42 
corona Wallich . « 6 
labiosa Wales . 39 
leidyi Wazles 4, 
lobostoma Leidy 6, 48 tau’ 
manicata Pen.  . 39 
marsuptformis Wallich 42, 44 
oblonga Hhrenb. . 5 
var. bryophila Pea. 37 
var. lacustris Pen. RON 
var, tenuis Pen. 36 
olliformis Lugerh. . 400 
oviformis Cash . . 6 
pyriformis Leidy . . 37 
var. bryophila Pen. . 37 
var: tenuis Pen. . 36 
rubesvens Pen. . 37 
i PAGE 
Difflugia subequalis Pen. 
40 (syn.), 41 
tuberculata var. minor 
Wales . . 4 
urceolata var. amphora 
Leidy . 39, 40 
DIFFLUGINE . . 36 
Diplochlamys Greif . 27, 30 
fragilis Pen. 31, 32 
gruberi Pen. . 3i 
leidyi Greeff ’ . 31 
timida Pen. 31, 32 
vestita Pen. : 31, 33 
Diplophrys timida Brown. 32 
Echinopyxis aculeata (Hhrenb.) 
Carter : . 42 
Euglypha Duj. 3, 4,5 
Frustulia Agardh 17, 20 
(Cyclostella) Kuetz. . 1? 
operculata Agardh 18, 20 
Gallionella ? (Pywidicula) 
Ehrenb. 17, 20 
operculata Ehrenb. . 18 
Heleopera Pen. 64, 65 
cyclostoma Pen. . . 65 
petricula var. amethystea 
Pen. : . 66 
sordida Pen. ; 63 
sphagni var. lwvis Waites 64 
Hyalosphenia inconspicua 
West . : . 53 
ovalis Wazles F . 55 
papilio Leidy : 55 
Lecythium mutabile (Bailey) 
Hopk. 4 . 25 
Logposa : 8 
Microcorycia Coshexelt 24, 27 
flava (Greeff) Cockerell . 25 
radiata (Brown) Hopk. 25, 27 
Nebela . 2 6, 63 
acolla Cash ‘ . 60 
barbata Cash 6, 58 (syn.), 60 
bigibbosa Pen. 5, 56 
bipes (Carter) Murray. 5 
