ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
477 
j3. Nemathelminthes. 
Germinal Zone of Ascaris megalocephala.* — Dr. von Wasielewski 
lias traced the genital tubes to their ends where they form a very fine 
coil. A simple membrane encloses a single row of large germ-cells. 
Lower down the membrane shows a plasmic layer and nuclei. Between 
the germ-cells and the membrane a distinct cellular layer is formed and 
the central germinal cells cease to be in a single row. In the centre the 
rhachis appears as a plasmic pillar. 
Even in the large cells of the single row the equatorial plate stage 
of karyokinesis was detected. The chromatin threads fall into cubical 
elements with each of which a spindle thread is associated. Sometimes 
these cubes divide and what looks like a double row of pearls is seen 
along the equator. 
The genital tubule includes, at some distance from its origin, a 
number of large cells of unknown origin and import. There are also 
residual bodies, which Lameere regards as due to extrusions of nuclear 
substance from the differentiating sex-cells. But they are least abun- 
dant where cell-multiplication is most active. The author regards 
them as the results of the degeneration of germ-cells in consequence of 
pressure and imperfect nutrition, and compares them with degenerations 
in the testicular canals of man in cases of local tuberculosis. 
Oxyuris Paronai and Cheiracanthus hispidus.j — Dr. von Linstow 
describes a new species of Oxyuris found on Branco, one of the Cape 
Verde Group, in Macroscincus Coctei , and he enters at length into an 
account of Fedtschenko’s species Cheiracanthus hispidus, sixteen specimens 
of which were found in the stomach of a Hungarian Pig. 
y. Platyhelminthes. 
Turbellarian in Underground Waters.^ — Prof. W. A. Has well 
reports an alloiocoele Turbellarian as inhabiting the underground waters 
of Canterbury, New Zealand. With two exceptions, one of which is 
very doubtful, all the members of this group are sea-dwellers. All the 
specimens examined by the author are devoid of eyes and completely 
destitute of pigment ; the largest are nearly an inch and a half long. 
Further details are promised. 
New Genus of Temnocephaleae.§ — Prof. W. A. Has well has a 
preliminary note on Actinodactylus , a new genus allied, at first sight, to 
Temnocephala , but having twelve tentacles and no eyes ; it was found 
in the branchial cavities of the burrowing land-Crayfish of Gippsland 
( Engseus fossor). In living examples the difference between it and 
Temnocephala is much more marked than in alcoholic specimens. 
Marine Planarians of New England |] — Prof. A. E. Verrill has 
brought together the scattered notes, descriptions, and sketches of the 
marine planarians of New England, made during more than twenty 
seasons of work at marine Invertebrates. He does not expect his paper 
to serve more than as an introduction to the study of a group, which has 
been much neglected by American naturalists. The author points out 
* Arch. f. Mikr. Anat., xli. (1893) pp. 324-37 (1 pi.). 
t Arch. f. Naturg., lix. (1893) pp. 201-8 (1 pi.). 
t Proc. Linn. Soc. N.S.W., vii. (1893) pp. 341 and 2. § Tom. cit., p. 342. 
[| Trans. Connect. Acad., viii. (1892) pp. 459-520 (5 pis.). 
2 l 2 
