72 THE ROTIFERA. 
passes, and its foot either thrown into one long curve or oddly bent zigzag fashion, it 
grubs among the sediment of the live-box ; and sometimes it glides gently away by the 
action of the coronal wreath, with its long toes trailing gracefully behind it, just like 
Scaridium eudactylotum. 
Length, ., inch. Habitat. Clear ponds and ditches, Hampstead Heath; Kew 
Gardens ; Woolston (P.H.G.); Clifton, Birmingham (C.T.H.) : not yery common. 
D. terractis, Ehrenberg. 
(Pl. XXI. fig. 2.) 
Dinocharis tetractis 5 = : Ehrenberg, Die Infus. 1838, p. 473, Taf. lix. fig. 2. 
SP. CH. Lorica vase-shaped, narrowing to the hind extremity, facetted, without 
spines ; foot and toes very long, together more than twice the length of the trunk ; spurs 
curved ; no spine between the toes. 
This species is extremely like D. pocillwm, differing from it chiefly in haying no spine 
between the toes on the last joint of the foot. The trunk viewed dorsally has a some- 
what triangular outline, the apex of the triangle being towards the foot, and is shorter 
in proportion to the foot and toes than it is in the former species. Mr. Gosse has ob- 
served in this species that the lorica runs off at the hind end into three, thin, transparent, 
and radiating plates, of which one is dorsal; and that this latter is not continued so far 
forward as the lateral plates, so that a transverse section shows no trace of the dorsal 
radiating one, but rather a slight depression between two gibbous swellings. This is 
well shown in fig. 1c, a transverse section through D. pocillum. Myr. Gosse has also 
seen many specimens of D, tetractis, in which the spurs on the penultimate joint were 
more or less deteriorated ; so that in some they were reduced to short tubercles, or even 
effaced altogether. These latter specimens were precisely Ehrenberg’s D. pawper, which 
can no longer, therefore, be entitled to rank as a species. 
Length. Up to ,); inch (P.H.G.). Habitat. Clear ponds and ditches throughout 
England and Scotland (P.H.G.; C.T.H.): common. 
D. coLuinsil, Gosse. 
(Pl. XXI. fig. 3.) 
Polychetus subquadratus (2). c 5 Perty, 7. Kenntn. kl. Leb. 1852, p. 45. Taf. 1. fig. 6a. 
Dinocharis Collinsii . = 5 - Gosse, Intell. Observer, vol. x. 1866, p. 269. 
Polychetus spinulosus 5 0 3 5 Archer, Quart. J. Mier. Sci. vol. viii. 1868, p. 72. 
SP. CH. Lorica depressed, sub-quadrangular, with serrated edges and eight dorsal 
spines ; spurs straight ; foot and toes short, together as long as the trunk. 
Though this Rotiferon is clearly a Dinocharis, it is a very singular one. The foot is 
short, the toes small, the lorica depressed, and a chitinous dorsal hood protects the head. 
The lorica is somewhat rectangular in shape, but broader in front than behind, with its 
fore corners rounded off, and its lateral edges serrated. At each hind corner a sharp 
spine projects, while six others rise from the dorsal surface. There is an outer pair 
attached to the shoulders, pointing down the back; and an inner pair, slightly decurved 
at the tips, rising from the central highest point of the lorica, and pointing diagonally 
outwards and upwards. A third pair, sharp and straight, rises from the hind end of the 
lorica, one on each side of the foot, and pointing outwards and upwards; while the first 
joint of the foot itself carries a pair of sharp chitinous spurs. The lorica is closed, much 
arched dorsally, highest in front, and flat on the ventral surface. The dense lorica, 
which is stippled in the central region, makes it difficult to define the internal structure; 
but Mr. Gosse, from whose Memoir (loc. cit.) this account is taken, succeeded in ob- 
serving a globose mastax, ample alimentary canal, and rich ruby eye. 
