INDEX. 71 
PAGE 
Nebela certesi Penard . 57 
cratera Wailes  . . oF 
dentistoma Pen. . 60, 61 
var. lacustris Wailes . 60 
var. lagentformis Playf. 
60, 61 
equicalceus Leidy . 4 
griseola Pen, : . 57 
lageniformis Wales 
58 (syn.), 59 
var. minor Wailes 58, 59 
martiali Certes 4, 57 
militaris var. tubulata 
Brown . 58 
murrayi Watles . . 57 
scotica Brown . 60 
scutellata Wailes . . 63 
tenella Pen. F . oF 
tropica Wailes . . 63 
tubulata Brown . . 58 
tubulata Pen. : . 58 
vitrea Cash ; 61 
var. minor Pen. . 62 
var. sphagni Wailes . 64 
NEBELINE ‘ : . 55 
Pamphagus mutabilis Bailey . 25 
Parmulina Pen. : . 27 
cyathus Pen. 27, 28 
obtecta (Gruber) Pen. . 28 
Fria. 176.—Pyzidicula operculata. 
- PAGE 
Plagiopyxis Pen. 44, 46 
eallida Pen. . 46 
labiata Pen. : 46 
Pontigulasia compressa 
(Carter) Cash 49, 50 
compressa Rhumbl. 49, 50 
elisa (Penard) Schout. . 50 
rhumbleri Hopk. . . 49 
Pseudochlamys patella Clap. 
& Lachm. . 26 
Pseudodifiugia fascicularis 
Pen. ‘ 54 
PSEUDONEBELINEZ  . . 66 
Pyxidiculd Ehrenb. 17, 18, 20, 21 
eymbalum Pen. 18, 23 
invisitata Averintz. 18, 22 
operculata (Agardh) 
Ehrenb. 18, 20, 21 
patens Clap. & Lachm. . 18 
Quadrula symmetrica 
var. irregularis Pen. . 62 
Quadrulella Cockerell . . 63 
symmetrica (Schulze) 
Cockerell ‘ . 63 
var. irregularis Pen. . 62 
Trigonopyxis (Difflugia) 
arcula Ff . 46 
Trinema enchelys (Hhrenb.) 
Leidy : . 53 
x 800. (After Ehrenberg, 1856.) 
