Part 5, 1916] AGARICACEAE 311 
Pileus grayish-brown, rarely paler. 
Stipe 1.5-2.5 cm. long. 16. O. serotina. 
Stipe 4 cm. long. 17. O. praedecurrens. 
Pileus fuliginous, paler when dry; stipe 3-4 cm. long. 18. O. pseudogrisea. 
II. SPECIES OCCURRING ON THE PaciFic coast 
Pileus pure-white. 
Pileus 2.5 mm. broad. 19. O. californiensis. 
Pileus 5-10 mm. broad. 
Stipe glabrous. ; 20. O. McMur phyi. 
Stipe whitish-pruinose. 21. O. subimmaculata. 
Pileus pale-orange or yellowish-ferruginous. j 
Pileus pale-orange; stipe glabrous. “22. O. aurantiaca. 
Pileus yellowish-ferruginous; stipe conspicuously tawny-strigose below. 12. O. campanella. 
Pileus brownish-gray at the center, with paler shades toward the margin. 23. O. Bakeri. 
Ili. SPECIES OCCURRING IN TROPICAL NorTH AMERICA 
Pileus entirely smoky-white; lamellae very distant. 24. O. distantifolia. 
Pileus white or whitish, differently colored on the disk. 
Disk reddish-brown; stipe scarcely 1 mm. thick. 25. O. convexa. 
Disk some other color; stipe 2-3 mm. thick. 
Disk pale-yellowish; hymenophore solitary. 26. O. petasiformis. 
Disk subfuscous; hymenophore densely cespitose. 27. O. euspeirea. 
Pileus some shade of yellow or orange. 
Hymenophore solitary or gregarious. 
Pileus lemon-yellow, 5 mm. broad; occurring among dead leaves. 28. O. citricolor. 
Pileus orange-yellow, often fading, 2-13 mm. broad; occurring among 
mosses. 14. O. fibula. 
Pileus stramineous with a grayish tint, 12 mm. broad. 29. O. myceniformis. 
Pileus dull-rosy-isabelline, 2 cm. broad. 30. O. cuticolor. —~ 
Hymenophore cespitose. 
Pileus pale-isabelline; stipe glabrous. 31. O. roriduliformis. 
Pileus yellowish-ferruginous to dull-reddish-yellow; stipe adorned 
below with brown hairs. 12, O. campanella. 
Pileus pale-avellaneous, 8 mm. broad, gregarious. 32, O. subavellanea. 
1. Omphalopsis papillata (Peck) Murrill. 
Omphalia papillata Peck, Ann. Rep. N. Y. State Mus. 51: 285. 1898. 
Pileus membranous, conic or campanulate, 2-6 mm. broad; surface papillate, pure-white, 
margin nearly even: lamellae strongly decurrent, few, distant, arcuate, white: spores sub- 
globose, 4-5 y: stipe glabrous, attached to the matrix by a few radiating white filaments, fili- 
form, white, about 2.5 cm. long. 
TYPE LocaLity: Gansevoort, New York. 
Hasitat: On sticks and fallen leaves in woods. | 
D1stRiBvUTION: Known only from the type locality. 
2. Omphalopsis pusillissima (Peck) Murrill. 
Ompbhalia pusillissima Peck, Bull. N. Y. State Mus. 116: 27. 1907. 
Pileus membranous, broadly convex or nearly plane, umbilicate, 2-4 mm. broad; surface 
glabrous, white, slightly striate on the margin when dry: lamellae few, distant, decurrent, 
white: spores subglobose or broadly ellipsoid, 5-6 X 4-5 uw: stipe slender, filiform, flexuous, 
glabrous, white, 6-10 mm. long. 
TYPE LOCALITY: Delmar, Albany County, New York. 
Hasitat: On humus and decaying twigs under pine trees. 
DISTRIBUTION: New York. 
3. Omphalopsis Rhododendri (Peck) Murriil. 
Agaricus (Omphalia) Rhododendri Peck, Ann. Rep. N. Y. State Mus. 27: 94. 1875. 
Omphalia Rhododendri Sacc. Syll. Fung. 5: 335. 1887. 
Pileus convex, umbilicate, 4-6 mm. broad; surface glabrous, slightly viscid when moist, 
white, margin striate: lamellae subdistant, arcuate, decurrent, white, beaded on the edges with 
gland-like protuberances: spores oblong or narrowly ellipsoid, 7.5 X 3 u: stipe white, roughened 
with minute, white, gland-like protuberances, slender, 12-16 mm. long. 
TYPE LOCALITY: Forestburgh, New York. ; 
Hasrrat: On dead trunks of Rhododendron maximum. 
DIstRIBUTION: Northern New York. 
