108 THE AMERICAN MONTHLY - [June, 
a. Body saccate, long, front large, tapering behind . . ¢ oe 
a. Body saccate, slender, ends obtusely pointed ; face prone, long, 
saccigera. 
a. Body rhomboid in outline; auricles great, globose . . . fpzlarzus. 
a. Body thick, dorsally arched; auricles small, slender . . . . ¢rdpus. 
6. Body subcylindric ; toes lone ee age A MM LDL IE 
6. Body fusiform ; foot invisible, toes minute win lace. pcos so Ss ug a eta 
6. Body fusiform ; foot long, toes short, pointed . . . . . . natas. 
6. Body trumpet-shaped ; toes conical, minute ) art. «jas ebeoae 
6. Body somewhat vasiform : toes lone: mastax very large . lacinulata. 
33. CopEus. 
Lumbar organs a stoutseta onteach side) Saw eas ee labiatus. 
Lumbar organs tubules setigerous at the summits. . . . . spicatus. 
Lumbar organs tubules not “setigerous : 2 ins | = hye DG HAV zinaaane 
Lumbar organs a single tentacle : ; antenna single s\ 8 oa) 2) GN earenahamen 
Lumbar organs wholly Wanting 2) oe a a 
34. PROALES. 
Foot and toes none. Parasitic in Volvox . . . « y Paernasanan 
Foot undeveloped ; toes minute ; body slender, ver Aniliean . . dectpiens. 
Foot stout; toes slender, pointed; proboscis large, fleshy . . . . felis 
Foot stout; toes slender, pointed ; back much Araneae . proboscis small, 
Libba. 
Foot stout, long, toes minute; body ovate . . .  petromyzon. 
Foot very ipeeuels toes minute ; body subcylindric, head hears . sordida. 
Foot and toes long, in profile sigmoid ; body cylindric or fusiform, 
tigridia. 
35. FURCULARIA. 
a. Toes twice the body length, unequal... ~: . ..) . )SNSiazaeraeaee 
a. Toes twice the body length, equal vee - 2 CGUalase 
6. ‘Toes nearly one- half the body length, stylate, Fete: straight .  gtbba. 
6. Toes about one-half the foot length, conical ; body fastest . Boltont. 
c. Toes blade-shaped, acute, fecueed: neuen with 2 teeth . forjficula. 
c. Toes blade-shaped, acute, decurved, not notched; marine . . mara. 
c. Toes blade-shaped, wider vertically than laterally, not notched, exszfera. 
d. Toes slender, straight, acute, front rounded, face oblique . . graczlzs. 
d. Toes slender, slightly curved, obtuse; neck strongly constricted, ceca. 
e. Toes minute, conical, foot inconspicuous ; no eye . OOO gpgemagiae 
36. EospHora. 
Head separated by a neck; auricles protrusible .-. . . . <=) e@mz7zcae 
37. DIGLENA. 
a. Toes straight, parallel-edged, abruptly pointed ; proboscis frontal, 
grandis. 
a. Toes straight, slender; body necked, slender . . . . gtraffa. 
a. Toes straight, long ; foot short, very thick; eyes 2, colorless, caudata. 
a. Toes straight, eure foot long, thick; body very Aa . . permollis. 
aa lioes straight, long, rod-like ; “body oblong : : biraphis. 
a. Toe str aight, short, projecting ventrally at right angles to the body, 
\ catellina. 
. Toes decurved, long; body in a leathery sheath, hunchbacked . g»7bdber. 
. Toes decurved, body not sheathed, long, cylindric, slender . clastopzs. 
. Toes incurved, slender ; proboscis Lane Pras . .  ctrcinator. 
. Toes scythe- -shaped ; body cylindric, each end ibtase . .« foretpatas 
Va aon 
