12 THE ROTIFERA. 
Ceylon. It isa remarkable Rotiferon, surpassing almost every other in the number and 
variety of its styles, sete, and cilia. In general shape it is something like a Brachionus, 
but its head is that of a Hydatina. There are only three styligerous prominences in 
the corona between the two usual wreaths, and these bear styles arranged fan-fashion 
and thickened at the base, as if each style passed through a short sheath; a form of 
style strikingly visible in the young animal, when the styles are short. The whole of 
the cavity leading to the buccal funnel is ciliated, and at its base is a ring of large 
curved styles, pointing upwards. On each side of the wedge-shaped opening, at the 
entrance to the buccal funnel, are large set set horizontally above one another in short 
sheaths, and fringed at their bases with minute vertical sete (fig. 1c). The trophi are 
malleate, and Mr. Gosse says that they are the exact repetition of those of N. clavulatus 
(Notommata clavulata) as figured by him in “ Phil. Trans.’ 1856, Pl. xvi. fig. 28. The 
rest of the nutritive system, as well as of the secreting and vascular systems, is obvious 
and normal. The ovary is horseshoe-shaped, with its germs set in a single line. 
There is a nervous ganglion just below the dorsal surface of the head, somewhat rect- 
angular in outline like that of Hydatina senta; and, like it, giving off nerve-threads at 
its corners, two of which doubtless pass to the large dorso-lateral antenne shown at the 
lower corners of the trunk in fig. 1. Mr. Gosse, in a side view, has seen that the 
nervous ganglion is a truncated pyramid, bearing the red eye on its summit. 
The Male.—JN. brachionus carries its egg for some time after exclusion, so that it is 
possible to identify the male with certainty. The male is very unlike its mother in 
shape and size, and a side view (fig. 1b) shows that the head slopes back to a hump, on the 
apex of which is a bunch of tactile sete. A nerve-thread from the nervous ganglion 
passes to these, and lies between two fine muscular fibres. A moderately sized sperm- 
sac ends in a ciliated penis just above the foot, which contains two large club-shaped 
glands. Close to the sac is a small contractile vesicle, the lateral canals of which can 
be readily traced on either side of the ventral surface.! 
Length, 1, inch. Habitat. Pondsand pools; Clifton (C.T.H.); Kingswood (P.H.G., 
T.B.): not common. 
N. cuavutatus, Ehrenberg. 
(Pl. XV. fig. 3.) 
Notommata clavulata . . Z Ehrenberg, Die Infus. 1838, p. 432, Taf. 1. fig. 5. 
SP. CH. Body sac-shaped; foot one-ninth of total length, wholly retractile within 
the ventral surface; trophi malleate. 
At the first glance one would say that this animal was an Asplanchna, which genus 
it greatly resembles in general shape, in brilliant transparency, and in the comparative 
emptiness of the trunk. But a little examination shows that the two are widely unlike 
in corona, trophi, and alimentary canal. On comparing, however, the apparently dis- 
similar creatures N. brachionus and N. clavulatus, it will be found that they are, in 
many important points of their structure, exact counterparts of each other. The corone, 
for instance, are closely alike, although N. clavulatus has a greater number of styligerous 
lobes, and lacks the ring of curved styles that lie round the base of the cavity of the 
corona in N. brachionus (fig. 1). The trophi are identical. The muscular and vascular 
systems are much alike; the latter, indeed, curiously so, for the sharp bend at right angles 
in the lateral canals, which is rendered necessary by the shape of N. brachionus, is 
repeated (needlessly, as it were) by N. clavulatus. The contractile vesicle in the latter, 
however, has much thicker walls, and is sluggish in action. The eye is seated on the 
1 Ehrenberg found a female with a cluster of male eggs; and, misled by their size and number, 
supposed that the issuing young were those of a Notommata which he named N. granuwlaris, and 
which he credited with laying its eggs on the backs of Brachionus pala and Notops brachionus. 
Leydig explained the error (oc. cit.). 
