96 
oof B 
c Dorsalantenna yery long and mobile; corona large.....macroceros 
d Dull brown, viscous; dorsal antenna large, top 
swollen.......... MSDN RN LIM WO pS LET SE 8) vac n leah tardus 
d Clear brown, not viscous; antenna long, stout. 
MIOTIONLOBS 2213/0 05 os o's in wes el biele ees baie sm 0 SRE hapticus 
e Spurs short, thick at base; toes usually retracted, not easily 
seen ; body tapering to the foot..elongatus. Sup. Weber 
e Spurs long, slender ; toes long, 3-jointed, usually extended : 
body not tapering..................trisecatus. Sup. Weber 
15. ActTinuRUS. I., 109. Sup. 8. 
One species os RO Salve eee alee eevee ane neptunius 
16. CALLIDINA. I., 109. Sup. 8. 
a Frontal column without hooks, (b) 
a Frontal column with 2 curved hooks................... bihamata 
a it * ‘¢ 1decurved, acute hook.......... pigra. Sup 
b Not commensal nor parasitic, (c) 
b. Commensal or parasitic, (f) 
b Incups and leaves of Jungermanniz, (i) 
b In mosses, (Sphagnum and others), (j) 
c Body without spines or points, (d) 
c Body with spines, posterior 8, rough, anterior 4; 
longitudinal ridges 14; toes 4, in 2............ 
uneqtial pairs ; teeth2............. cataracta. Q. 1898, 75 
a Four spurs, 20n top of foot................ quadricornifera, Sup 
d Two spurs or none, (e) 
é Body transversely corrugated ; teeth 2; spurs minute, 
eT ee eae cla oie Ng i ticalnna er Ranece ia sacri bidens 
f On larva of Psephanus, (g) 
f On Gammarus and Asellus, (h) 
g Dorsal antenna ended by many, small, setiferous, 
GOsled  Sleva MONS ow. eels es che awe oles socialis. Sup 
h Dorsal antenna small, tip a ciliated cup with 
hood-like projection...... magna-calcarata. Q., 1892, 378 
h Dorsal antenna large, tip 3-lobed, without sete........ parasitica 
i Teeth 2 on one ramus, 3 on other........0.0000-85 symbiotica. Sup 
i Teeth 5 on one ramus, 6 on other.......... reg yr Leitgebii. Sup 
j Body with spines, points, knobs, or frontal horns, (k) 
j Body with longitudinal skin-folds, (1) 
j Body without skin-folds, (0) 
k With 2 fronto-lateral, fleshy horns........cornigera. Q., 1893, 196 
THE AMERICAN MONTHLY [May 
Body brown, (d) im 
Body gray, (e) 
Gradually tapering to the £oOC 6) ciiies. ccc aot Mae vulgaris — 
Suddenly attenuated to the very long, slender foot ; 
body nyaline atthe ends. oo a ee macrurus 
. eur ho eee 
