ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
289 
to check the growing practice of giving new names to every slight 
variety ; for this purpose, and also for reference, his plate of fourteen 
figures is very instructive and useful. 
Metopidia pterygoida, a new Rotifer.* * * § — Mr. M. F. Dunlop de- 
scribes and figures this pretty and peculiar new species with wing-like 
expansions of the lorica, but otherwise allied to Perty’s Notogonia 
ehrenbergi. 
N ematohelminthes. 
Classification of Nematoda.t — Dr. von Linstow criticises Schneider’s 
old classification into Polymyarii, Meromyarii, and Holomyarii, the de- 
fects of which have been previously indicated by Biitsckli and others. 
Yon Linstow distinguishes three families : — 
I. Secernentes. The lateral line bears a ridge or cushion with a 
narrow base, which expands internally and projects beyond the muscles. 
In both cushions or in one there is a longitudinal vessel opening ven- 
trally at the excretory pore. Examples : — Ascaris osculata, Oxyuris 
vermicularis, Ankylostomum duodenale, &c. 
II. Pesorbentes. The lateral lines have broad areas, about as thick 
as the musculature, without a vessel, and apparently suctorial. These 
forms do not, when mature, inhabit the food-canal of their host. Ex- 
amples: — Filaria tricuspis, Dracunculus medinensis, Eustrongylus gigas , 
&c., &c. 
III. Pleuromyarii. The lateral lines have neither cushions nor 
special lateral areas ; the oesophagus lumen is often a narrow chitinous 
tubule, and in some there is no intestine. Examples : — Trichocephalus 
unguiculatus, Gordius tolosanus, &c. 
The same paper includes a description of several new species. 
Excretory System of Nematodes.! — Prof. N. Nassonow has followed 
Kowalewsky’s injection method in studying the excretory organs of 
Ascaris megalocephala and Oxyuris flagellum. Powdered carmine or 
sepia injected into the cavity of the body of A. megalocephala is found 
aggregated in two pairs of giant stellate cells, connected with the 
lateral lines, and by irregular branches with the intestine. The lateral 
lines of Oxyuris flagellum consist of three rows of cells, the innermost 
cells being traversed by the excretory canal. 
Alleged Nematode-Parasites of Truffles.§ — M. J. Chatin examined 
a number of truffles (Tuber melanosporum and others) in which Nematodes 
occurred, and found that the worms were Pelodera strongyloides Schm. 
and Leptodera terricola Duj. ; that is to say, two saprophytic forms 
which had taken to a new habitat. They are not truly parasitic in the 
truffle, nor are they possible parasites of man. 
Molin’s Genus Globocephalus.|| — Dr. von Linstow has studied the 
intestinal parasite of the pig, to which Molin gave (1861) the name 
Globocephalus longemucronatus. His careful investigation shows that the 
parasite belongs to the genus Ankylostomum . 
* Journ. Quekett Micr. Club, vi. (1897) pp. 325-7 (1 pi.), 
t Arch. f. Mikr. Anat., xlix. (1897) pp. 608-22 (1 pi.). 
X Zool. Anzeig., xx. (1897) pp. 202-5 (3 figs.). 
§ Comptes Bendus, cxxiv. (1897) pp. 903-5. 
il Zool. Anzeig., xx. (1897) pp. 184-7 (4 figs.). 
