THE 



MONTHLY MICROSCOPICAL JOURNAL. 



SEPTEMBER 1, 1871. 



I.— On a New Botifer. By C. T. Hudson, LL.D. 



Plate XCIV. 



A ROTIFER hunter should never pass a pond without trying it, no 

 matter how often he has heen disappointed before. For example, 

 here is a pond close to my house, which, so far as I can remember, 

 has never yielded anything worth catching for many summers, and 

 yet this. July I have taken in it in one dip several specimens of 

 Synchxta, Asjplanchna, Brachionus, and Anursea, as well as of a 

 new and very extraordinary rotifer. 



On hunting over the bottle with a hand lens before taking it 

 home, I readily recognized the first four, while the latter I sup- 

 posed to be some new and unusually large species of Polyarthra ; 

 but on placing a specimen under the microscope I for a moment 

 doubted whether it was a rotifer at all, and not a larva of some one 

 of the Entomostraca. A brief examination showed the animal to 

 be a true rotifer with a splendid trochal disk and cihated chin, and 

 with internal organs much like those of Triarthra, but with an 

 external form of a most unusual character ; for it possesses six 

 well-defined limbs containing powerful muscles, and terminated not 

 by cilia but by fan-shaped plumes of fringed hairs, and is in these 

 respects so utterly unlike any other rotifer, that, though it has 

 many points of resemblance to the Hijdatinxa, I am quite puzzled 

 where to place it. 



I propose to call it Pedalion mira, from the oar-shaped limb 

 with which it steers its way like an ancient trireme ; occasionally 

 however improving on its antique type by striking a succession of 

 vigorous slaps with all its limbs in concert, and darting through the 

 water with such speed as to clear quite sixty times its own length 



EXPLANATION OF PLATE XCIV. 



Fig. 1. — Front view, showing the dorsal antenna, eyes, double row of cilia 

 round the trochal disk, and the mouth lying between them and 

 above the ciliated chin. 

 „ 2. — Side view. 

 „ 3. — Dorsal view. 

 „ 4. — Pseudopodium ; ventral surface. 

 All the figures are on the same scale, and represent a magnification of about 

 300 linear. 



VOL. VI. K 



