ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 
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(7 mm. in length) ; S. regularise in which the tactile prominences are 
exceedingly regular, and the epidermis is especially thick anteriorly, 
so that the head is not constricted from the body as in other species ; 
Krohnia foliacea , with a single pair of lateral fins of remarkable size, 
extending from before the abdominal ganglion to the middle of the 
caudal segment; and K. pacifica, which is easily distinguished by its 
faintly yellowish-green epidermis, and ovaries of the same colour. 
Rotatoria. 
Rotifer Commensal with Caddis-Worm.* — Mr. Hy. Scherren re- 
cords having found Callidina parasitica inside the case of the larva of 
Phryganea grandis. This Callidina is usually found attached to the gill- 
plates of Gammarus pulex and Asellus aquaticus, where it takes advantage 
of the current of water over the gills. 
Mastigocerca hamata sp. n.f — Dr. 0. Zacharias figures and describes 
this new species found in a gathering of plankton from a small lake in 
Upper Silesia. Its principal characteristic is a long curved frontal 
hook ; the toe is nearly as long as the body. 
Nematohelminth.es. 
Epidermic Nuclei of Anguillulidse.J — M. Joannes Chatin discusses 
the structure of the epidermis or hypodermis of Nematodes, concerning 
which there has been prolonged dispute. The integument of a Nema- 
tode in the adult state, or in some types at certain stages of development, 
shows beneath the cuticle a granular layer of a plasmodial appearance, 
with scattered nuclei. This epidermis is interpreted by some as a case 
of free nuclei without protoplasmic territories. Others regard it as only 
secondarily syncytial, produced by a coalescence of cellular elements. 
The second view was maintained by Chatin in 1888 and 1891 ; but, as he 
has been recently cited as an upholder of the first interpretation, he has 
restated his position. Moreover, he has found clear corroboration in 
studying Tylenchus , Heterodera , and various Anguillulidas. There the 
epidermis or hypodermis is at first distinctly cellular, but as it becomes 
older the boundaries disappear and the territories fuse. 
New Classification of Gordiidae.§ — Prof. L. Camerano divides Gor- 
diidae into four genera, the diagnoses of which take especial account of 
the posterior ends of male and female, and of the external structure of 
the cuticle. These genera are : — Chordodes (Creplin) Mobius, with 
27 species, Parachordodes g. n., with 15 species, Paragovdius g. n., with 
4 species, and Gordius Linn., with 13 species. There remain 30 species 
inquirendae. 
The author thinks the family should be made into an order Gordiacea, 
with, as H. B. Ward suggests, two families: — Nectonemidae and Gord:- 
idae. His views as to general relationships are indicated in this Stamm - 
baum : — 
* Nature, lvi. (1897) p. 224. 
t Forschungsberichte Biol. Station Plon, v. (1897) p. 8. 
j Comptes Kendus, cxxv. (1897) pp. 57-9. 
§ Zool. Anzeig., xx. (1897) pp. 225-9. 
