ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
67 
buccal proboscis, which is highly extensile, and is armed at its extremity 
with a minute stylet. While the tentacles and epidermis appear to ally 
it to the Temnoceplialeae, it differs from them in having an anterior 
sucker, and a bursa copulatrix, as well as in wanting contractile ex- 
cretory sacs. 
5. Incertse Sedis. 
Rotifers of the Rhine.* — Herr R. Lauterborn has for some years 
been studying the fauna of the Rhine and the associated basins. At 
present he reports on the Rotifers, of which about 100 species were 
found. These he discusses in relation to their habitats in flowing or 
stagnant water, &c. The following new forms are described : — Mastigo- 
cerca hudsoni sp. n., M. setifera sp. n., Chromogaster testudo g. et sp. n., 
Dictyoderma hypopus g. et sp. n., Brachionus rhenanus sp. n. 
Alpine Rotifers.! — Dr. 0. E. Imhof notes the occurrence of Floscu- 
laria regalis and Melicerta Janus in Alpine lakes. They have hitherto 
been found in England only. Two species of Notholca , N. labis and 
N. scapha, are also notable finds. Altogether fifteen species of Eurhya- 
line Rotifers have been found in lofty water-basins of central Europe. 
Three have a very wide distribution : Polyarthra platyptera in twenty- 
six Alpine lakes, Anursea coclilearis in sixteen, and Notholca longispina in 
forty-one. The author touches lightly on the problems raised by the 
fauna of these high-lying lakes, but a full discussion is promised. 
New Rotifers.! — Mr. J. Hood describes Floscularia spinata , which 
is distinguished by the presence of short spines on the circumference of 
the coronal cup ; Polyarthra aptera differs from P. platyptera , the only 
other known species of the genus, by its want of the lateral appendages ; 
Brachionus tridens is marine in habitat, and is chiefly peculiar for having 
only three spines on the occipital edge of the lorica. 
Mr. D. Bryce § describes Metopidia parvula from Epping Forest ; it 
is only 1/350 in. when extended. 
Echinoderma. 
Ophiuroids of North Sea.||— Mr. J. A. Grieg gives an account of the 
twenty-four species and one variety of Ophiuroids collected during the 
Norwegian North-Sea Expedition. The absence of genital fissures in 
Ophiopus arcticus is confirmed ; the fold noticed by Lyman appears to be 
a scar due to repeated ruptures, for while the species is perfectly capable 
of reproduction when it has a disc-diameter of 3 mm., the fold is not 
found in any individual which is not, at least, twice as large. 
Ophiopus arcticus .f — The structure of this species has also been 
investigated by Herr T. Mortensen, who points out that of the species 
which have been said to resemble Ophiopus , Ophiomusium pulchellum 
and 0. flabellum have no bursae at all, and must be placed in a special 
* Zool. Jahrb. (Abtli. Syst.), vii. (1893) pp. 254-73 (1 pi.). J 
f Biol. Centralbl., xiii. (1893) pp. 607-12. 
x Journ. Quek. Club, v. (1893) pp. 281-3 (1 pi.). § Tom. cit., pp. 284 and 5. 
|| Den Norske Nordhavs-Expedition, xxii. Opbiuroiden, fob, Christiania, 1893, 
41 pp., 3 pis., and 1 map. 
*lf Zeitschr. f. wiss. Zool., lvi. (1893) pp. 506-28 (2 pis.). 
