30 AN GIOSPERMAE DICOTYLEDON ES 



66. R. nivalis L. This species is circumpolar. Lindman states that the 

 flowers are first protogynous, and afterwards homogamous. The mechanism is 

 similar to that of R. acris, but the corolla is deeper and narrower, and the floral 

 receptacle longer and more convex. Onjhe upper surface of each petal there are 

 longitudinal hollow swellings. The diameter of the flower which is 18 mm. in 

 Arctic Siberia is considerably less on Nova Zemlia according to Ekstam. 



Andersson and Hesselman state (' Bidrag till Kanned. om Spetsbergens o. Beeren 

 Eil. Karlvaxtflora,' p. 49) that it flowers and sets fruit normally in Spitzbergen. In 

 specimens collected by Vanhoffen in Greenland (Abromeit, 'Bot. Ergeb. v. Dry- 

 galski's Gronlandsexped.,' pp. 30-1) there were a large number of shrivelled and 

 seedless fruits in addition to the properly developed ones. Ekstam (' Blutenbiol. 

 Beob. a. Spitzbergen/ p. 23) describes the feebly fragrant flowers as 10-12 mm. 

 in diameter; and the light or dark yellow petals as about half as long again as 

 the sepals, which are thickly covered with dark-brown woolly hairs. He found the 

 flowers to be protogynous-homogamous. 



Visitors. Ekstam noted one small fly in Nova Zemlia, and a large number 

 on the flowers of one plant in Spitzbergen. 



67. R. lanuginosus L. (Herm. Muller, ' Fertilisation,' p. 78, ' Weit. Beob.,' 

 I, p. 321; Knuth, { Bloemenbiol. Bijdragen.') The floral mechanism agrees with 

 that of R. acris, but in spite of the larger flowers insect-visits are more numerous 

 only in the lighter parts of the woods. 



Visitors. The following have been observed by Hermann Muller (H. M.) and 

 myself (Kn.). A. Coleoptera. (a) Coccinellidae\ i.Coccinella quattuordecimpunctata 

 Z., nect. skg. (H.M.). (b) Dermesiidae : 2. Byturus fumatus L., freq. po-dvg. (H.M.). 

 (c) Elateridae : 3. Athous haemorrhoidalis F. (H. M.), with its head in the base 

 of the flower, (d) Nitidulidae : 4. Meligethes aeneus F., freq., gnawing petals and 

 stamens (Kn., H. M.). B. Diptera. (a) Bibionidae : 5. Dilophus vulgaris Z. (H. M.). 

 (b) Empidae: 6. Empis livida Z., skg. (H. M.); 7. E. trigramma Mg., skg. (c) 

 Muscidae : 8. Anthomyia sp. (Kn., H. M.) ; 9. Hylemyia conica Wied. (H. M.) ; 

 10. Scatophaga stercoraria Z. (d) Syrphidae: 11. Ascia lanceolata Mg., occasional 

 individuals (H. M.) ; 12. A. podagrica F., freq. (H. M., Kn.); 13. Bacha elongata F., 

 occasional individuals (H. M.); 14. Cheilosia albitarsis Mg. (H. M.); 15. C. pubera 

 Zett. (H. M.) and other sp. (H. M.) ; 16. Eristalis arbustorum Z. (Kn.); 17. Melano- 

 stoma mellina Z., in large numbers (H. M.); 18. Pipiza notata Mg. (H. M.); 19. 

 Syrphus lunulatus Mg. (Kn., H. M.); 20. S. nitidicollis Mg. (H. M.); 21. S. ribesii 

 Z. (Kn.); 22. S. venustus Mg., in large numbers (H. M.); 23. Volucella pellucensZ. 

 (H. M.); all po-dvg. C. Hymenoptera. Aptdae: 24. Andrena cingulata F. $>, 

 po-cltg. (H. M.); 25. A. parvula K. $, skg. (Kn., H. M.); 26. Apis mellifica Z. jjf, 

 po-cltg. (Kn.) ; 27. Bombus terrester Z. 5, skg. (H. M.) ; 28. Eriades florisomnis Z. 6, 

 skg. (H. M.) ; 29. Halictus flavipes F. 5, skg. (Kn., H. M.) ; 30. Osmia bicolor 

 Schr. 5, po-cltg. and skg. (H. M.). 



Loew observed in the Berlin Botanic Garden. Hymenoptera. Apidae: 

 Eriades florisomnis, $ skg., 5 po-cltg. 



68. R. montanus Willd. (including R. Villarsii DC). (Herm. Muller, ' Alpen- 

 blumen,' pp. 133-5.) The flowers are about equal in size to those of the last 

 species, and are protogynous, but automatic self-pollination is possible. 



Visitors. Loew observed in Switzerland (' Beitr'age,' p. 57). Diptera. (a) 

 Asilidae-. 1. Lasiopogon cinctus F. (b) Syrphidae: 2. Cheilosia antiqua Mg., 

 po-dvg. 



