108 THE ROTIFERA. 



in Noteus and in many Anuraa, and all minutely shagreened. The bead 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 N. triptera. The trophi are on the plan 

 common in the Euchlanidce, 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 (Ecistes Stycjis and (E. brachiatus. It is of lively manners. P.H.G.] 



Length, T i y inch. Habitat. London ; South Devon ; Dundee (P.H.G.) : rare. 



M. KHOMBOIDES, Gosse, sp. nov. 

 (PI. XXV. fig. 10.) 



[SP. CH. Lorica rliomboid-ovate in outline ; dorsal surface tcctiform, lower behind, 

 ending in an obtuse point ; ventral surface flat. 



This seems to come between oxysternum and triptera. The oesophagus 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, T J T inch. Habitat. North London (P.H.G.) : very rare. 



M. TRIPTERA, Ehrenberg. 



(PI. XXV. fig. 7.) 

 Mctopidia triptera .... Ehrenberg, Die In/us. 1838, p. 478, Taf. lix. fig. 12. 



[SP. CH. Lorica nearly circular, as vieived 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 M. 

 lepadella, and so it is if viewed sidewise. But an instant turn, or a slight change of 

 level, and the broad planes come into view, with an effect that surprises. Each 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-like 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 Euchlanis. 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. 



