ROBERTSON FLOWERS & INSECTS, ASCL. TO SCROPH. 579 



honesta Cr. '^ ^ s.\ (5) Alcidamea producta Cr. ^j', s. ; (6) Oismia albi- 

 ventris Cr. 9> s. & c.p. ; (7) Nomada luteola Lep. (^, s. Andreni'doi, 

 (S) Augochlora pura Say '^ , s. Sz c.p. ; (9) Andrena, sp. "^j s.; (10) A. 

 sayi Rob, 9 1 c.p. ; (i i) A. polemonii Rob. 'J, $ , s. & c.p. ; (12) Halictus 

 pilosus Sm. 9, s. ct c.p. 



Diptera. — Syrp/iida\ (13) Mesograpta marginata Say, f.p. ; (14) Rhin- 

 gia nasica Say, s. i!s: f.p. 



Lepidoptera — Rhopalocera^ {\^') Colias philodice Godt.. s. ; (16) Ni- 

 soniades brizo Bd.-Lec, s. 



Coleoptera. — Coccinellidoi^ (17) Megilla maculata DeG., f.p. 

 HTDKOPHYLLACE^. 



Hydrophxlbim Virginiciim* L, — The flowers are male in the 

 first stage. The stigma, when receptive, surpasses the anthers. 

 On account of the erect coroHa lobes and the hairy filaments, the 

 nectar can be obtained most conveniently by a tongue about 9 

 mm. long. 



May II, 12, 31 and 33 I observed the following visitors: 



Hymenoptera. — Afidce, (i) Bombus virginicus Oliv. 9? (2) B. ri- 

 dingsii Cr. 9; ab. ; (3) B. vagans Sm. 9 '1 (4) B. americanorum F. 9 ; 



(5) Anthophora abrupta Say 9 — ^^^ ^* AndrenidK^ (6) Augochlora 

 pura Say 9> c.p. 



Diptera. — Syrphidce, (7) Rhingia nasica Say, f.p. 



Hydrophyllum apfendiculatum Michx. — The flowers are pro- 

 terandrous as in the preceding. They are pale blue with white 

 centres. The throat is more widely open than in H. Virginictcm, 

 and the filaments are not hairy. There is, therefore, less difl!i- 

 culty in reaching the nectar. Accordingly, we find more short 

 tongues, although bumble-bees remain by far the most numerous 

 guests. The flowers and flower-clusters are much more con- 

 spicuous, and the plants grow in larger patches. 



May 3, 14 and 16 I observed the following visitors : 



Hymenoptera. — Apida^ {1) Apis mellifica L. ^ , s. & c.p., ab. ; (2) 

 Bombus virginicus Oliv. 9 V 1 s- ! (S) ^' separatus Cr. 9 § ? s. <.V c.p., 

 ab. ; (4) B. ridingsii Cr. 9 ? i s. & c.p., ab. ; (5) B. vagans Sm. 9 » s. ; 



(6) B. americanorum F. 9> s., ab.; (7) Synhalonia honesta Cr. 'J, 9? §• 

 ^'c.p., ab.; (8) S. speciosa Cr. 'J),s.; (9) Megachile brevis Say(^, s., 

 once; (10) Osmia lignaria Say 9?s., ab.; (11) O. albiventris Cr. 9 ? s. 

 & c.p., ab. Andrenid(£^ (12) Andrena erigenise Rob. (^9» s. & c.p.; 



* See Sprengel, "Das entdeckte Gelieimniss," 104, Tab. xix. 46 & 47. 



