580 TRANS. ST. LOUIS ACAD. SCIENCE. 



(13) Agapostemon radiatus Say 9 ? s- & c-P-i (14) Augochlora pura Saj 

 9, s. & c.p.. ab.; (15) A. lucidula Sm. 9- s., once; (16) Halictus 4- 

 maculatus Rob. 9 7 s., once; (17) II. pectoralis Sm. 9»s.; (i8)H.coria- 

 ceus Sm. 9?s., ab.; (19) H. pilosus Sm. 9iS., once; (20) H. confusus 

 Sm. 9- s., once. Eume7iid<x, (21) Odynerus tigris Sauss., s. ; (22) O. 

 foraminatus Sauss.. s. 



Diptera. — Empidcn, (23) Empisnuda Lw., s., ab. Syrphid(K^ (24) 

 Rhingia nasica Say, s. & f.p., ab. ; (25) Eristalis flavipes Walk., s. ; (26) 

 Criorhina intersistens Walk., s. ; (27) Xylota chalybea Wied. Antho- 

 myidK, (28) Anthomyia sp. 



Lepidoptera. — Rhopalocera^ (29) Phyciodes nycteis D. &H.; (30) 

 Pamphila zabulon Bd.-Lec; (31) Pholisora hayhurstii Edw. — alls. 



BO KKAGINACE^. 



Mertensia Virginica DC. — I have found the flowers open on 

 four or five successive days. On the morning of the first day the 

 anthers are still closed, while the stigma appears receptive. On 

 the second day, and sometimes on the third, the anthers discharge 

 their pollen. Then the flowers hang on for a day or two, adding 

 to the conspicuousness of the inflorescence. The flowers are 

 hardly to be regarded as proterogynous, cross-fertilization being- 

 secured by the stigma being widely separated from the anthers 

 and striking the bee in advance of them. 



Nectar is secreted by four glands alternating with the carpels. 

 The style is somewhat flattened at base, and the carpels are in 

 pairs on each side of it. In the wider intervals thus formed, two 

 of the glands are situated, and are much larger than the others, 

 rising as high as the carpels. 



The bell-shaped border opens into a tube which is from 14 to 

 15 mm. long. The blue color and the size of the tube, together 

 with the pendulous position of the flowers, indicate an adaptation 

 to the larger bees, but butterflies sometimes hang on the flowers 

 aud draw out their honey. In the following list all of the insects 

 are intruders except Boiiibus^ Anthophora^ and Synhalonia. 



On 16 days, between April 19 and May 13, I observed the fol- 

 lowing visitors : 



Hymenoptera. — Apidm^ (i) Apis mellifica L. ^ , c.p. ; (2) Bombus 

 separatus Cr. 9) ''•; (3) B- ridingsii Cr. 9 ' s. ; (4) B. vagans Sm. 9? 

 s. ; (5) B. americanorum F. 9 1 s. ; (6) B. pennsylvanicus DeG. 9 i s. ; 

 (7) Anthophora abrupta Say cJ* 9 1 s. ; (8) A. ursina Cr. c? 9 ? s. ; (9) 



