406 KEFEKBNCB NOTES. 



49. " Bull. Soc. Vaud.," xiv, p. 211, 1876. 



50. " Rendic. E. Istit. Lomb.," ser. 2, xii, p. 694. 



50a. Asper and Heuscher have quite recently shown, through the use of 

 a " pelagic " net, that the pelagic faunas of lakes are far more prolific in mi- 

 croscopic animal forms than has hitherto been supposed. A drop of water 

 from Lake Ziirich was estimated to contain ten individuals of Anuraea foli- 

 acea, eight of Anuraea longispina, sixty of Geratium hirundlnella, and mill- 

 ions of Dinobryon forms and Asterionellas, besides various heliozoans, roti- 

 fers, and crustaceans. Identical results were obtained under all the most 

 varied conditions of light (darkness) and water, in the open lake and along 

 the shallower shore-line (" Zoologischer Anzeiger," June 19, 1886). 



51. "Nature," June 11, 1885. 



62. "Am. Joum. Science," 1871, p. 161. 



53. " Bull. Soc. Vaud.," xiii, xiv, 1874, 1876. Dr. Henri Blanc enumer- 

 ates the following twelve species of Rhizopoda as entering into the compo- 

 sition of the deep-water fauna of Lake Geneva (seventy to one hundred and 

 twenty metres) : Amoeba proteus, A. verrucosa; A. radiosa, Difflugia pyri- 

 formis, D. urceolata, D. globulosa, Hyalosphenia cuneata, Arcella vulgaris, 

 Centropyxis aculeata, Pamphagus hyahnus, Actinophrys sol, and an unde- 

 termined large Difflugia. All or most of the above forms have been ob- 

 served by Leidy in the surface-waters of the United States, and it is re- 

 marked that the species indicated to be rare by Leidy are also rare in the 

 deep waters of the lake (" Bull. Soc. Vaud.," ser. 2, xx, p. 287). 



64. "Am. Joum. Science," 1871. 



55. " Anniversary Address, London Geol. Soc," 1881. 



65a. Probably the most striking and convincing evidence indicating con- 

 vergent modification is presented by the Australian fauna, where, among 

 the numerous implacental forms, we have such remarkable reproductions 

 of the distinctive types seen among the Placentalia, although based upon 

 an entirely different type of structure, and arising independently of the 

 other. 



56. " Paleontographical Soc. Reports," 1884. 

 67. "Ann. Mag. Nat. Hist.," 1874, xiii, p. 222. 



58. Heilprin, "Proc. Acad. Nat. Sci.," Philadelphia, March 4, 1884. 

 69. "Anniversary Address, London Geol. Soc.," 1881. 



60. Medlicott and Blanford, " Geology of India," part i, p. 282. 



61. Seelcy, " Q. Journ. Geol. Soc," London, 1883. 



62. Dawson, " Am. Joum. Science," third ser., xx, pp. 403 et seq. 



63. Anodonta Jukesii, from the Old Red Sandstone of Ireland. Pro- 

 fessor Hall recognises in the Cypricardites-Catskillensis of Vanuxera, from 

 the Oneonta Sandstones of the State of New York (Middle Devonian), a 



