Page:Midland naturalist (IA midlandnaturalis01lond).pdf/147

I do not propose any elaborate description of examples, and shall merely mention, with a few notes, those which have occurred to me in the neighbourhood of Nottingham, and which are tolerably common everywhere. I have of course met with our old friends Œcistes, Floscularia, Meliecrta, and other sedentary or case-inhabiting hinds, According to my experience, the sheath of Œcistes is generally of an irregular, somewhat broken form, and more or leas dingy with adhering vegetable matter. Last March I found one with three eggs at the bottom of the sheath, close to the supporting stalk, Floscularia, with its long pedicel, might easily be taken at first sight for a large Vorticella. Round the opening at the free extremity, there are five, or occasionally six, knob-like processes, each armed with a radiating bundle of long cilia, finer than any spun glass. These long filaments, however, have no concern in producing currents towards the mouth; such currents being evidently due to vibratile cilia within the mouth or gullet itself. The species which I have most frequently met with is, F. cornuta, distinguished by a little horn or feeler at the hack of one of the knob-like processes. The eggs cluster in a group of two or three about the pedicel; and through their thin covering may often be seen the eye-spots of the young ones. The outer sheath is perfectly transparent, and has a refractive power nearly the same as that of water. Consequently it is mlmost invisible, except by means of particles collecting on its delicate surface. Meliecrta possesses a ciliated disk, arranged in wavy lobes, presenting a front aspect not unlike the stylish cap one sees in portraits of Mary Queen of Scots. Nothing can exceed the beauty of the general effect, when this graceful wreath is in fall action, Still more noteworthy is the animal's building talent. Into a little pit near the head, particles of selected matter are swept from the water, and there moulded into conical pellets, which the animal then deposits in regular courses one upon another, like rounds of bricks, and so builds up its case, These cases, of a reddish brown colour, are easily detected with the naked eye, attached by one end to branches of myriophyllum, or roots of lemma, By chipping cut the bits of vegetation to which the several specimens cling, four or five may be got together in the field of a two-thirds objective; and then the display, under spot-lens illumination, is simply magnificent. A zoophyte trough made specially shallow from front to back, is the most convenient for showing them. With regard to Stephanoceros, or the Crown-horned Rotifer, it should be noticed that the lobes of the wheel-apparatus take the extreme form of so many tentacles, fringed with whorls of moving cilia. The protecting case is highly transparent. Few specimens have rewarded my search in this neighbourhood.

We, now pass from these kinds which envelope themselves in a sheath of various structure, into which they can retire at will, to the free-swimming group. The latter constitute by far the larger division of