92 THE ROTIFERA. 
the dorsal plate. The outline of the dorsal portion of the lorica, when seen directly 
from the front or rear (fig. 4c), is triangular; the section, so obtained, having a base 
just twice its height. There is a well-marked occipital notch (fig. 4b) in the dorsal 
plate, through which a short, stout, dorsal antenna usually protrudes. Dr. Grenacher 
has detected two dorso-lateral antenne close together ‘‘lying near the crest of the 
lorica.”” Ehrenberg says that there are no sete on the foot; but I have never failed to 
find two when using dark-field illumination. The rest of the structure requires no 
further notice, as it is a tolerably close repetition of that of H. lyra.. 
This is one of the choicest of microscopic objects, when shown in a dark field; 
especially when it is quietly gliding over and round a few tangled alge. Its strange 
armour is now invisible, and now blazes out as it catches the light; while the ruby eye, 
the daintily-tinted stomach studded with glittering drops on canary-coloured quiltings, 
the ruddy intestine softened by the tremor of its ceaseless cilia, and the restless head 
crowned with an ever-varying halo of flashing sete, form a picture that once seen can 
never be forgotten. 
There is a variety of H. triquetra, with a lower vertical plate, which I have met 
with now and then; and which, on several occasions appeared to have but one long seta 
on the foot. Possibly this is Leydig’s H. wniseta (Pl. xxiii. fig. 3). 
Length. Up to ~; inch. Habitat. Clear ponds and ditches: not uncommon. 
E. DEFLEXA, Gosse. 
(Pl. XXIV. fig. 1.) 
Euchlanis deflera c S : Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 200. 
[SP. CH. Outline of lorica ovate ; ventral gape wide, equal, with deep walls ; 
toes broad, blade-shaped ; lateral horns of incus straight. 
This is a large and very beautiful species. It is not to be distinguished at first sight 
from a true Huchlanis, but the carapace, which is highly arched, turns in at the lateral 
edges, and after proceeding for a space horizontally, z.e. across the ventral surface, is 
bent down at a right-angle to a considerable width and then terminates, as if we might 
suppose the ventral plate to have been originally flat and continuous ; then to have been 
slit down the middle, and each side to have been bent down at a line midway between 
the slit and the outer margin. Thus the abdominal cavity is enlarged, and the viscera 
are protected only by the common integument which is stretched across from edge to 
edge. This being flexible, a variation of contained space is allowed, for development of 
egos, for distension of the alimentary canal, &c., which, in Huchlanis, is obtained by the 
flexibility of the skin that connects the two plates. The lorica is almost circular behind, 
where a very minute central notch admits the two sides to overlap in the slightest pos- 
sible degree. The foot issues, of course, from the ventral hiatus; it bears two toes, which 
are thin, flat, and wider inthe middle part. The penultimate joint of the foot proper has 
on its dorsal side a curved projection, which arches over a deep excavation. It carries two 
pairs of long sete, one or both of which are sometimes wanting. Lach toe has a cor- 
rugated mucus-gland (?) running through it. The broad head is composed of many 
(ten 2) transparent globate lobes; the front is divided into several pairs of lobes, which 
carry bundles of cilia. The three strong lines which (with the front) form a square, 
reaching behind the mastax, are puzzling, but I believe they represent the wide, clear 
brain. The sacculate stomach is enormous, with two gastric glands; and two glands, 
beside, are attached to the mastax: there is a small, distinct intestine in which the epi- 
thelial cilia may occasionally be seen; a great ovary, with embryonic vesicles, and 
sometimes one (or more) dark ovum maturing. The branchial tubules, two or more, 
contorted and very loosely twisted, carrying four vibratile tags on each side, open by 
two distinct mouths on each side, into an ample contractile vesicle, just before the cloaca, 
whose periods are very irregular, even in the same individual: now emptying once in 
two minutes, then several times per minute. Many museles are seen, some indubitably 
