Miscellaneous, 199 



State), and which he regards as identical with all those which have 

 been mentioned above, always excepting Nemertes polylioiila, 

 Schmarda. 



This view is adopted by Dr. von Marenzeller *, who believes that 

 the Nemcrteaus mentioned by Kraepelin f as occurring in the Avater- 

 supply of Hamburg belong to the same species. 



It was probably the same worm again which was met with first 

 at Wurzburg and again in Livonia by von Kennel J, in the Lake of 

 Geneva by du Plessis, and perhaps even in the neighbourhood of 

 Bagamoyo, on the east coast of Africa, near Zanzibar, by Dr. 

 Stuhlman §. 



There is nothing which need astonish us in a geographical distri- 

 bution like this if we think of many of the analogous facts which 

 are known for a certain number of freshwater Rhabdoccolos. Many 

 Hirudinea are without doubt more widely distributed than has 

 hitherto been believed jl. The same is true of the species of Hijilra^ 

 which are found by travelling naturalists in countries widely distant 

 from one another, if only they take the trouble to look for them ^. 

 A host of Rotifers are in the same case. Lastly the freshwater 

 Crustacea furnish very remarkable examples in this respect. Thus 

 Ctjclops Lemkarti, G. U, Sars, so widely distributed in Europe, is 

 met with in Senegal, Madagascar, Ceylon, Sumatra, Celebes, and 

 Australia**. Branchijnis auritus, Koch, which I recently mentioned 

 as occurring in Madagascar ff, likewise exists in Central and Eastern 

 Europe, in Egypt, the Sahara, North America, Florida, Texas, 

 Mexico, the Antilles (San Domingo), and at Port Natal. Thus 

 Darwin's views as to the dispersion of freshwater forms, which were 

 so just, become more and more confirmed %%. 



At all events, peculiar interest is afforded by the fluviatilc Nemer- 

 tean observed by von Kennel in Livonia. For this case really 

 exliibits in a striking manner the method of penetration of a marine 

 worm into fresh water. The Nemcrtean in question was found in 

 an old branch of the Embach, an afiluent of Lake Peipus. Now 

 there is no room for doubt that Lake Peipus is (like Lake Paleostom, 



* Zool. Jalu'buchev (Systematik), Ikl. iii. 



t ' Abliandl. a. d. Geb. der Naturwisscnschaf't, lierausgegeben vuni 

 Naturw. Vereiue in Hamburg,' Bd. ix. Heft 1 . 



X Sitzuugsb. der Naturf. Gesellsch. bei der Uuiv. Dorpat, Bd. viii. 

 Heft 3. 



§ Sitzuugsb. der k. Akad. der Wiss. Berlin, Bd. xlix. (Dec. 0, 1888). 



II An obliging communication from Dr. llaphael Blancliard enables 

 me to auuouuce the occurrence in Chili of Gloxsiphonia tessellata, O. F. 

 Miiller — the very leech which I have shown to be disseminated by the 

 Palmipeds (Compt. Ileud. .Soc. de Biol. 30 Janvier, 1892; Ann. & Mag. 

 Nat. Hist., July 1892). 



^ Hydra, which is so well known in Europe and the United States, 

 is t'oimd everywhere, although it is hardly possible to distinguish the 

 species ; it occurs in Victoria, in Australia (von Lendenfeld), New Zealand 

 (Coughtrey), Zanzibar (Stuhlmann), and the Azores (Th. Barrois). I am 

 likewise able to report the existence of Hydra in Senegal, near Rufisque, 

 where it was obtained by M, (^hevreux in 1890. 



** Bull. Soc. Ent. de France, stance du 24 fevrier, 1892. 



tt J. de Guerue aud J. Richard, Bull. Soc. Zool. de France, vol. xvi. 

 27 octobre, 1891. 



XX ' Origin of Species,' Chap. xii. 



