406 REFEEBNCB NOTES. 



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



50. " Kendic. K. 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 Ziirioh was estimated to contain ten individuals of Anursea foli- 

 acea, eight of Anursea longispina, sixty of Ceratium hirundinella, and mill- 

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

 fers, and crustaceans. Identical results were obtained under all the mos*; 

 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. 



52. " Am. Journ. 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, DifBugia pyri- 

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

 Centropyxis aculeata, Pamphagus hyalinus, 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. Journ. Science," 1871. 



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



55a. 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. 



66. " Paleontographical Soc. Reports," 1884. 



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



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



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



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



61. Seeley, " Q. Journ. Geol. Soc," London, 1888. 



62. Dawson, " Am. Journ. 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 Gatskillensis of Vanuxem, from 

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



