CHARLES ROBERTSON 149 
Orchis spectabilis (6:52-3).—Blooms May 6-19; 2 visitors 
observed, May 13; Ma, R. 
Long-tongued Bees (2)—Bomb.: Bombias separatus 9, Bombus 
americanorum 9. 
Spiranthes gracilis (6:51-2).—Blooms August 27—October 7; 
2 visitors observed, September 3, 4; Ma, W. 
Long-tongued Bees (1)—Bomb.: Bombus americanorum ¢. 
Short-tongued Bees (1)—Panurg.; Calliopsis andreniformis 9. 
OROBANCHACEAE 
Orobanche uniflora.—Blooms April 27—May 28; 1 visitor ob- 
served, May 16; Ma, W. 
Long-tongued Bees (1)—Bomb.: Bombus americanorum 9. 
OXALIDACEAE 
Oxalis corniculata.—Blooms April 14—July 7; 18 visitors ob- 
served, May 22—June 10; Mi, Y. 
Long-tongued Bees (4)—Ap.: Apis; Ceratin.: Ceratina ¢ 9; 
Megachil.; Alcidamea simplex ¢, Osmia pumila 9, se. 
Short-tongued Bees (9, 2, se)—Halict.: Chloralictus albipennis, 
pilosus fq, pruinosus fq, tegularis, versatus, Evylaeus foxii, pee- 
toralis, Odontalictus, Seladonia. 
Diptera (1)—Syrph.: Mesogramma marginata sf. 
Lepidoptera (4)—Nymphal.; Phyciodes fq; Papilion.: Pieris, 
Pontia; Hesperi.: Pholisora catullus. 
Oxalis stricta——Blooms June 1—November 7; 12 visitors ob- 
served, June 18, August 4, 22, October 9; Mi, Y. 
Long-tongued Bees (2)—Bomb.: Bombus americanorum 9%; 
Eucer.: Melissodes bimaculata 9. 
Short-tongued Bees (2, 2, se)—Halict.: Chloralictus versatus; 
Panurg.: Calliopsis andreniformis. 
Diptera (5)—Syrph. (f, n): Mesogramma marginata, Syritta; 
Empid.: Parempis; Bombyli.: Sparnopolius, Thlipsogaster. 
Lepidoptera (3)—Papilion.: Pieris; Hesperi.: Pholisora catul- 
lus, hayhurstii. 
Oxalis violacea (6: 272-3).—Blooms April 6—June 10; 31 vis- 
itors observed, April 23-May 17; Mi (Ma), R. 
Long-tongued Bees (12)—Ap.: Apis; Bomb.: Bombias auri- 
comus 9, Bombus americanorum 9; Ceratin.: Ceratina ¢ 9, fa, 
Zaodontomerus 4, fq; Megachil.: Monilosmia ¢, Osmia pumila 9, 
fq; Nomad.; Centrias americanus ¢, Holonomada superba ¢ 9, faq, 
