1889.] BOTANICAL GAZETTE. 3<>3 



Diptera — Emfidce : (13) Empis sp., s. Syrp/iidw: (14) 



Eristalis flavipes Walk., f. p. 



Lepidoptera — Rhopalocera : (15) Nisonides JuvenalisF '. s. 

 Coleoptera — Scar abac idee: (16) Euphoria sepulchralis F. 



f. p. 



Ceanothus Americanus L.— The flowers and their pedicels 

 are white. The stems are surmounted by many umbel-like 

 clusters of flowers, and many stems are crowded togeth- 

 er ; so that insects are attracted for a considerable distance 

 by what seems one large bunch of white flowers. Each hood 

 of a petal encloses an anther, and the petal and stamen rise 

 together. The peculiar form of the petals is associated with 

 a peculiar disposition of the sepals, which serve to conceal 

 the nectar, so as to limit the visitors to a more diligent set 

 than would predominate if the nectar were more freely ex- 

 posed. The nectar is secreted on a broad disk which is con- 

 cealed by the sepals remaining strongly closed over it. A 

 petal and an anther have thus to be liberated through the 

 narrow slit between two sepals, and the form of the blade ot 

 the petal is to allow it to escape and to free the anther with 

 it. In character of visitors the plant resembles those Um bel- 

 li ferae in which the disk is covered by the incurved petals. 



Visitors (observed on five days between June 19 and 29): 

 Hymenoptera— Afidce : (1) Bombus sefaratus Cr. ? , s. and 

 c/p. ; ( 2 )B. pennsylvanicus DeG. ? . c. p. ; (3) Ceratina dn- 

 pla Say S , s. ; (4) Megachile brevis Say 9 , s. and c. p. ; b) 

 Hcriades carinatum Cr. 9 , s. and c. p. ; (6) Nomoda tncerta 



Cr. 9,s.; (7) Calliofsis andreniformis Sm. *, s. Andttn- 

 idce: (8) Macropis sp. i, s. ; (9) Augochlora fura bay 9 , S. 

 and c. p. ; (10) Halictus perforate Sm. 9 , s. and c. p. ; ("l 

 //. similh Sm. 9 , s. and c. p. ; (12) H.flavi P es F 9 , . and 

 c p, ; (13) //. confusm Sm. 9 , s. and c. p. ; (14) f • ■ **«« 

 Cr. 9 ,8. and c p. ; (15) Sphccodes confertus Say ? * 9 s. . 



Prosofis a finis Sm. S ? , s. ; (i7\ P -p 



Eumenitt 



s. Vesfifa: (18) Polities pallipes St. *arg. ***** < •• 



(19) Eumenes fraternus Say; (20) Odyngus W ®™^ 

 (2i) O.fulvi/es Sauss. ; (22) O. dorsal, F. ; 23) ^**T 

 <W«5 Sauss.; (24) O. c^/ormis Sauss. ; (2S) °-.f^ es ™ 



«« /^n /^ ^L..„„./,r„H>»c Snuss. Crabromdd: (271 



Sauss. ; (26) <9. _^ 



(28I 6? v !'/><?/"$ 4-notatus S ay ; 

 1 ' -. - /%•'— 



(29) <9. /r**tef« Rob'. ;. (30) 0. emargmatus Say. *™£- 



<&< (31. 32) Cerceris spp. ; (33 -6. <*£* J ;^/ ? 4 



'/> 



( 3S ) C.c<mparCt.\ (36) Crufr 



