445 
Floscnlaria pelagica, &c. By C. F. Bousselet. 
I found this remarkable little animal in the small lake on Keston 
Common, which derives its clear water from Caesar’s Well, a few hun- 
dred yards further on, in company with A. yriodonta and other free- 
swimming Rotifers. I collected only from one spot, near the surface 
of the water, taking no weeds at all from the lake, which is fairly 
deep, and found about twenty specimens in the single bottle I filled. 
This, then, is a thoroughly free-swimming Floscule, quite at home 
in the open water, propelling itself slowly by means of a wreath of 
vibratile cilia, just like the Ploima, but instead of being driven for- 
ward, it invariably swims backwards, and looks then like a long, narrow, 
sternwheel boat, except that the wheel is at the head. The whole 
body and the gelatinous case are white, of glassy transparency, which 
is an additional character of pelagic animals. 
Its nearest ally is Floscularia mutabilis of Hudson, from which it 
differs in many particulars, as will be seen by the specific characters, 
and from the description. 
The animal as a whole is greatly elongated and very narrow, 
measuring 1/85 in. to 1/65 in. from head to end of foot, and not 
more than 1 /450 in. at the widest part of the body. The foot when 
extended is generally one and a half to twice as long as the body, but 
of course it can contract, and is then more or less reduced in length. 
The corona, fig. 1 b, is circular without any lobes, and fringed all 
round with a wreath of fairly long lashing cilia, by means of which the 
animal swims slowly through the water. The characteristic stiff setae 
of Floscules are not apparent at first ; they are seated on five fleshy 
prominences, one of which is dorsal, within the ciliary wreath, and in 
a direction at right angles to, and across the coronal cup. The animal 
has the habit of sometimes contracting the lower part of the cup, by 
which action the rim of the cup becomes slightly everted, and the 
setae stand out, slanting upwards, and are then visible above the corona. 
The setae are short, only reaching three-quarters across the corona ; the 
dorsal prominence and setae are slightly larger than the others. 
Two small white globules near the rim of the dorsal side of the 
corona I at first thought might represent the eyes, but 1 found a 
number of very similar globules on various parts of the corona. A 
very small dorsal antenna is situated on a pimple about midway on 
the dorsal side of the coronal cup, as shown in fig. 1 c, a. The 
lateral canals and vibratile tags are present, but 1 could not find the 
contractile vesicle. 
In other respects the anatomy of the animal is exactly like that of 
other Floscules ; at the bottom of the coronal cup is the usual semi- 
circular band of very fine vibratile cilia, bounded at each end by a 
knob bearing a bundle of larger flagella ; then comes the diaphragm, 
with the buccal orifice, and the undulating elastic tube hanging down 
into the crop ; the jaws have two teeth as usual. Eight narrow 
muscular bands run from the rim of the corona to the tip of the 
foot. The foot is smooth when extended, hut transversely wrinkled 
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