ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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of Br. angular is), Biplois sculp turata (?), Monostyla incisa (?), Monostyla 
bicornis (?), Monostyla pygmsea (?), Brachionus mirabilis, Biarthra mono - 
styla (g. et sp. n.). 
Danish Rotifera.* * * § — Dr. Wesenberg-Lund has a preliminary report 
on free-swimming rotifers, of which lie has observed 175 species in the 
neighbourhood of Copenhagen. He has also studied in particular the 
males and the modes of reproduction in their natural condition, as con- 
trasted with artificial cultivations, and found that a period of increased 
parthenogenetic activity always precedes the appearance of the males 
and the production of fertilised resting eggs. The sexual period varies 
in different species, but the majority in Denmark appear to have it in 
September to October ; the temperature of the water has no influence in 
this respect. Contrary to the accepted belief, the author found some 
rotifers, such as Brachionus pala and angularis, bearing male and female 
eggs at the same time. The resting eggs are the fertilised eggs, but the 
author has observed also sexual periods when no resting eggs were pro- 
duced, although males were abundant. 
Hematohelminth.es. 
Life-History of Gordius, j — Dr. von Linstow showed some time ago 
that in the same pool one may find the embryonic stages of Gordius 
tolosanus Duj. encapsuled in larvae of Sialis lutaria and Gloeon dip ter um, 
the larval stages in the aquatic beetle Pterostichus niger, and the sexual 
adults free in the water. In the present paper he gives a list of eighteen 
insects in which the larvae of G. tolosanus occur. He also gives a list of 
over a dozen which he has shown to be hosts of the larvae of Gordius 
aquaticus L. ; the embryos occur in larval lampreys, and probably in 
small fishes. It is difficult to understand how certain of the insects 
(grasshoppers, Carabus, Procrustes, &c.) which are not aquatic, become 
infected, or how the larvae get from them into the water. When the host 
is Bytiscus marginalis, the problem is less obscure. In the same paper 
the eminent parasitologist discusses Oxyuris biuncinata from larval 
lampreys, Ascaris Myxines from the hag, Spiroptera mugientis from Bana 
mugiens, and Cercaria ericetorum from Xerophilus ericetorum, — all new 
species. In an appendix he takes note of Camerano’s recent monograph 
on Gordiida3. f 
Nematodes from Madagascar.§ — Dr. von Linstow describes new 
species of Ascaris, Physaloptera, Pieter aids, Filaria , Spiroptera, Oxyuris , 
Gordius, Mermis, and Echinorhynchus from Madagascar animals, extend- 
ing the familiar observation that each species has its particular parasites. 
Platyhelminthes. 
Turbellaria of Concarneau.|| — Dr. 0. Fuhrmann found 29 species of 
Turbellaria in the Bay of Concarneau, and of these five are new, viz. 
Plagiostoma Fabrei, the largest representative of the genus, PI. violaceum, 
Monoophorum durum, Macrorhynchus cceruleus , and Microstoma lucidum. 
* Zool. Anzeig., xxi. (1898) pp. 200-11. 
t Arch. Mikr. Anat., li. (1898) pp. 747-64 (1 pi.), 
t Mem. R. Accad. Torino, xlvii. (1897) pp. 339-419 (3 pis.). 
§ Arch. Naturgescli., lxiii. (1897) pp. 27-34 (2 pis.). 
11 Zool. Anzeig., xxi. (1898) pp. 252-6. 
