48 Verm . 
XV. VERMES. 
mechanical point of view, but found not to be determined by any simple 
mechanical factors or relations of form; Jennings. 
The first stages in development (formation of centrosomes, nutrition of 
ovum, and its maturation) in the three kinds of ova, viz. : — the partheno- 
genetic ones which become females, the parthenogenetic ones which become 
males, and the fertilized ones which become winter eggs--, of Asplanchna 
priodonta ; Erlanger & Lauterborn. Experiments for producing the 
different kinds of eggs at will in Hydatina scuta , shewing that a female, 
when well fed after leaving the egg, produces females parthonogenetically 
and continues so to do even if it is afterwards badly fed, whereas if badly 
fed to begin with male eggs are produced parthenogenetically however the 
after-conditions be changed ; N usbauh. The influence of the oxygenation 
of the water on rate of development and of temperature on the number of 
eggs produced is also shewn experimentally. 
Impregnation of the ova in Hydatina senta, the spermatozoa boring 
their way through the membrane of tho ovary from the coelom of the 
female, into which they were injected by the male ; Sadones [compare a 
similar process in a Turbellarian, p. 22 of this record]. 
Sporozoa (stages of Euglena ?) parasitic in intestinal cells of Hydatina 
senta ; Leussen. 
Commensalism: of Rotifers with caddis worms ; Scherren. 
Tube-building of Melicerta ringens. Int. J. Micr. (3) vii, pp. 285-287. 
Method of preparing rotifers : modification of Rousselet’s ; Zograf. 
GEOGRAPHICAL DISTRIBUTION. 
Spitzbergen : Fresh- water rotifers, 19 species Bdelloida , 6 Ploima , in 
ponds which often frozen for nine months of the year ; Bryce. 
Greenland: 84 species of fresh-water Rotifers, 4 of them new to 
Greenland; Vanhoffen, p. 175, &c. ; presence of Synchceta baltica and 
Mastigocerca stylata , Gosse, which only known before in the North Sea 
and Baltic; Vanhoffen, p. 276. 
Arran: a new Rotifer; Dunlop. 
Schleswig-Holstein: rotifers; Zacharias (1). Ponds of Sandfort, 14 
species ; Zacharias (2). 
Belgium : Kinroy : 6 spp. Rhizota ) 8 spp. Bdelloida , and 23 spp. Ploima ; 
Lam ee re. 
Switzerland: Rotifers of L. of Chavonnes; Pitard. Geneva neighbour- 
hood: 6 male rotifers, not previously described; Weber. 
Hungary: L. Balaton: 41 species (12 new); Daday (2). 18 Lakes in 
the Tatra Mountains : 23 species rotifers ; Daday (3). 
New Guinea: list of species; Daday (1). 
E. Africa: 16 spp. Rotifers (5 new), and 3 Oastrotricha ( 1 new); Collin. 
America: — New Jersey: shallow pool near Trenton, 6 new species; 
Stokes. L. Erie: Sandusky Bay: enumeration of 39 additional species 
making a total of 106 species ; Kellicott. 
SYSTEMATIC. 
A. — ROTIFERA, s.s. 
Asplanchna papuana , n. sp., New Guinea; Daday, Math. term. Ertes. 
Magyar Ak. xv, p. 132. 
A. priodonta , development of parthenogenetic and fertilised eggs; 
Erlanger & Lauterborn. A. herrickii , oarly development, includ- 
