. Lorica with an arched frontal plate (v). 
. Lorica entire, open at each end, cylindric (w). 
. Lorica entire, hemispheric or three-sided . .. «ol. i@eckieareiage 
. Lorica entire, formed of 2 plates, a dorsal and a ventral (yy). 
. Lorica entire on the back, front open, gaping behind . Mytilia, 56. 
. Lorica split down the back, each end open (aa). 
. Lorica pyriform, vasiform or cylindric, entire; frontal plate subcircular 
THE AMERICAN MONTHLY [ April, 
. Foot wanting; lorica with spines or elastic sete (s). 
. Foot not transversely wrinkled, not wholly retractile (¢). 
. Foot transversely wrinkled, and wholly retractile (c c). 
. Frontal edge always, the anal sometimes, spinous . . Azurea, 62. 
. Frontal edge six-spined ; often produced behind . . Notholca, 63. 
Lorica without spines, but with long, rigid styles . . Hretmiza, 64. 
Lorica without an arched frontal plate (2). 
or hook-like (44). 
. Lorica subspherical or pear-shaped ; ventral aspect slit; frontal plate a 
hook 0. eye ee pe ea eee 1 ea 
. Lorica compressed 5, toe single.) 4.) 3) 1) 2 0.) 1). oe 
. Lorica depressed, entire ; toes 2. . . « Metopidia, 54. 
. Body fusiform, or irregularly thick, aaite curv el toe single, with acces- 
sory basal stylets)! a - . » + & 2 | Mastigocexer eee 
. Body cylindrical, curved (x). 
Toes 2, symmetrical, side by side. . » Rattulas, As: 
Toes 2, hollow, unequal, triangular super posed plates . Colopus, 41. 
. Lorica plates dissimilar, forming 2 unequal body cavities, Hachlanzs, 49. 
Lorica with deep lateral longitudinal sinus covered by flexible mem- 
brane (2). 
z. Lorica subcylindrical in outline; toes2 . . . . . Cathypna, 50. 
zg. Lorica subcylindrical in outline; toe single . . . . Monostyla, 52. 
z. Loricaa long ellipse, closed behind ; toes 2, is «la Diener 
aa. Lorica oblong ; spinous; eye single". 9/0.) 2) 0) a See 
aa. Lorica not spinous; eye wanting sates Ure 282 
aa. Lorica dorsal only, ventral surface aes . . |. a DDi@seieom ace 
aa. Lorica of 2 plates, ventral flat, dorsal arched . . . . JDcplois, 48. 
66. Lorica dense, shagreened, facetted, with projecting plates or dorsal spines, 
RRRAR 
. 
Dinocharts, 42. 
. Lorica, thin, smooth, without spines or plates ; frontal plate hook-like, 
Scar7idium, 43. 
. Lorica sometimes posteriorly spinous, smooth ; frontal plate subcircular, 
Stephanops, 44 
. Foot ending in a ciliated cup (d@). 
. Foot ending in 2 toes (ee). 
. Lorica subcircular, entire, flattened . .. . . . . Fterodina, 58. 
. Lorica without elevated ridges; toes very small . . Brachtonus, 60. 
. Lorica facetted and covered with points . . . . . . Woteus, 61. 
SPECIES. 
1. FLOSCULARIA. 
Lobes none . . ww) ois je Nile ee a ecaammaaeaaae 
Lobes 2, short; coe very ‘Shore mee eevee is 5 bua rel gene 
Lobes 3, well-developed ; setz short but vibratile’ .: .), .. ligemembezase 
Lobes 3, the HORSES ga ges: 2, large, flexible o>, ce ti a play 5 alee enna 
Lobes 3, body =, to 7; inch; coronal depressions deep, rounded, 
tr ilobata. 
Lobes 3, body ;!; inch; corona symmetrically dotted . . . algzcola. 
