ROBERTSON FLOWERS .C INSECTS, ASCL. TO SCROPH. 591 



reach some of the nectar, and they might drain it but for the op- 

 position of the sterile hlament. Butterflies also steal the honey, 

 but they, as well as the little bees, are by no means certain to touch 

 the anthers and stigmas. 



On 10 days, between May 28 and June 36, I observed the fol- 

 lowing visitors : 



Hymenoptera. — ApidiM, (i) Apis mellifica L. ^ ; (2) Bombus ameri- 

 canorum F. 9 § ? (3) B- pennsylvanicus DeG. 9j one; (4) Anthophora 

 abrupta Say (^9 ? (S) Synhalonia atriventris Sm. y ; (6) S. honesta Cr. 

 (^; (7) S. speciosa Cr. 9 — alls.; (8) Ceratina dupla Say yjC.p.; (9) 

 Megachile montivaga Cr. (^9, s. ; (10) M. brevis Say $7 s. ; (n) Alci- 

 damea producta Cr. |^ 9 - s. & c.p., 9 reversing to receive pollen in ven- 

 tral scopa; (12) Osmia albiventris Cr. 9>s. ; (13) O. montana Cr. 9? 

 s. Andretiidce, (14) Agapostemon nigricornis F. 9? c.p.; (15) Halictus 

 coriaceus Sm. 9 1 c.p. ; (i6) H. confusus Sm. 9>c.p. 



Lepidoptera. — Rhopalocera, (17) Papilio troilus L. ; (iS) Colias phi- 

 lodice Godt. Sphing-idce, (19) Deilephila lineata F. — all s. 



Ccleoptera. — Scarab(Xid(f^ (20) Trichius piger F., f.p. 



Alesograpta mar£;tnata Say (Syrphidse) gleans stray pollen, which is 

 scattered npon lower Hp. 



Pcntstcmon 'pubescens Soland. — The flower is male in the first 

 stage, as in the preceding. The corolla tube measures about 15 

 mm. and is much narrower than in P. Icevigatus. The narrow 

 part measures about 6 mm. The wide part has two longitudinal 

 folds beneath, which alone almost close the entrance. Then the 

 sterile filament, which is more hairy than in P. Icevigatus^ and 

 the hairs on the lip, also, aid in closing the mouth of the flower. 

 The effect of these modifications is that a longer tongue is re- 

 quired to reach the nectar conveniently. 



The flower blooms somewhat earlier than the foregoing and 

 marks the time of appearance of the males of Anthophora ab- 

 rupta^ which are the principal visitors, as far as I have observed. 

 This bee only inserts its head far enough to hide its eyes, and re- 

 ceives the pollen on its hairy face. 



On 6 days, between May 12 and June 3, 1 captured the follow- 

 ing insects on the flowers : 



Hymenoptera. — Apid(K^ (i) Bombus vagans Sm. 9i (2) B. america- 

 norum F. 9 \ (3) Anthophora abrupta Say c^-, ab. ; (4) S_)'nhalonia spe- 

 ciosa Cr. 9 ; (s) S- honesta Cr. (^\ (6) Ceratina dupla Say 9? crawling 

 into tube; (7) Alcidamea producta Cr. rf, do. ; (8) Osmia atriventris 

 Cr. ^9, do.; (9) O. distincta Cr. 9, do. 



