108 THE ROTIFERA. 
in Noteus and in many Anure@, and all minutely shagreened. The head is deep, form- 
ing three lobes, all ciliated. In retraction the two sides of the lorica close on each 
other, leaving within a large clear space, exactly as in many Coluri, to which a further 
resemblance is borne by the position and direction of the foot and toes; the former in- 
clined forward, and the latter bent abruptly backward. A rather small brain carries an 
eye as large as half the mastax (possibly two suffused, since in some specimens two are 
observed), pale but rich, transparent rose-red. In rotating a narrow, parallel-sided, 
truncate lip is seen thrust out in front, as in MW. triptera. The trophi are on the plan 
common in the Huchlanide, and neighbouring families. 
I first obtained the species in an ornamental water near London in 1849; recently 
in a ditch at Coffinswell, near Torquay, and in water from the Black Loch, Dundee, in 
company with cistes Stygis and C4. brachiatus. It is of lively manners.—P.H.G.] 
Length, ;4, inch. Habitat. London; South Devon; Dundee (P.H.G.): rare. 
M. RHOMBOIDES, Gosse, sp. nov. 
(Pl. XXY. fig. 10.) 
[SP. CH. Lorica rhomboid-ovate in outline ; dorsal surface tectiform, lower behiegd, 
ending in an obtuse point ; ventral surface flat. 
This seems to come between orysternum and triptera. The esophagus is long, and 
often thrown into curves. The gastric glands are peculiar, being placed at the ends of 
two long threads, probably tubular, which are seated on the corners of the stomach, the 
globular glands themselves being affixed to the lining of the lorica.—P.H.G.] 
Length, ;},; inch. Habitat. North London (P.H.G.): very rare. 
M. trptera, Hhrenberg. 
(Pl. XXV. fig. 7.) 
Metopidia triptera a C S 0 Ehrenberg, Die Infus. 1838, p. 478, Taf. lix. fig. 12. 
(SP. CH. Lorica nearly circular, as viewed dorsally, dilated into three wide, but 
thin, wings, one dorsal and two lateral. 
The aspect of this tiny living jewel, viewed dorsally, is almost exactly that of MZ. 
lepadella, and so it is if viewed sidewise. But an imstant turn, or a slight change of 
level, and the broad planes come into view, with an effect that surprises. Hach of these 
is, speaking loosely, a semi-oval, formed of two thin glassy plates, soldered into one for 
about half their width, then diverging to constitute, with the like structure of the vertical 
plate, a sub-cylindrical sheath, in which the organs and viscera are inclosed. The foot 
finds its exit by a sinus excavated out of the lower part of the cylinder, whose fore end 
is truncate for the extrusion of the head. This is surmounted by a broad chitinous 
hood descending in front to a sharp edge (as usual hook-lke in lateral perspective), quite 
distinct from the tripterous lorica, within which its base is slightly retractile. It is con- 
spicuous in all aspects. From above, the ciliate front, with its minute crimson eyes, one 
at each extreme lateral joint, is clearly discerned through its transparency. 
It is a most exquisite little creature, of crystal brilliance, and sprightly in manner, 
without being swift. It swims little, but scrapes and pokes in the parasitic floccose. 
Here, as it turns and twists deviously about, we see constantly changing aspects of the 
three shining planes, whose surfaces and edges are ever crossing each other, all visible 
through each other, from their perfect translucency. Thus, though the difficulty of 
resolving the organic details of the active atom is augmented rather tantalisingly, one 
cannot but be charmed by the beauty and variety displayed. I have seen one, slowly 
gliding in a straight line, go on revolving on its axis, bringing the six surfaces into view 
in quick succession, with a striking effect. On another occasion one came sidling up to 
a noble Huchlanis. The contrast, and yet the resemblance, was curious; the one could 
have lain comfortably within the ample mastax of the other.—P.H.G.] 
Length, ;}, inch. Habitat. Sandhurst (Collins) ; Woolston; Dundee (P.H.G.): rare. 
