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on to the back of a female, and running all over her like a great 
parasite, frequently squeezing himself into the space between the 
dorsal and basal plates of the lorica of the female before actual coition 
takes place. He also secretes a glutinous material from his foot, by 
which he anchors himself to the body of the female, twirling round on 
his own axis at a short distance away. 
Size: — Total length of female adult rotifer, 1/70 in. Length 
of body and anterior spines only, 1/90 in. Width, 1/143 in. 
Length of male, 1/167 in. 
Rhinops orhiculodiscus. PI. VII. fig. 4. 
It is difficult to determine in which genus, whether Eydatina or 
Rhinops, this new rotifer should be placed. It is evidently a form 
intermediate between the two, since, in different points of its anatomy, 
it combines the characters of both. The corona is that of a Rliinops 
with the proboscis and terminal eyes absent, whilst it resembles a 
Eydatina in the fact that it possesses both a dorsal antenna and two 
lateral antennae. On account of the structure of the corona, I propose 
to place it provisionally in the genus Rhinops, and to name it 
R. orhiculodiscus. 
I found it in October 1889, in great numbers, in water from the 
peat bogs amongst the mountains of Donegal, behind Moville. In 
the following year I was unable to obtain a single specimen. In the 
same pool were Mastigocerca hicornis , Einocharis detractus, Diglena 
forcipata, and Pterodina reflexa. In another pool nigh to the same 
place was found Gonochilus volvox. 
The corona is the most characteristic feature in the anatomy of 
this rotifer. It is a perfect circle in shape, set at an obtuse angle to 
the ventral surface. It presents a deep cup-like cavity, round the 
inner edge of which runs the outer ciliary wreath. The inner ciliary 
wreath consists of large cilia placed on the summit of two tapering 
cushions which approach each other at the lower part and surround 
the buccal orifice. The long dorsal proboscis seen in R. vitrea is in 
this species entirely absent, as also are the eye-spots. The corona is 
in fact that of a Rhinops with the dorsal proboscis obliterated. 
The ventral surface is flattened, the dorsal surface, on the other 
hand, swelling out with a fine sweeping curve into a globular form, 
well seen when the creature is viewed from the side (fig. 4 h ), and 
then suddenly diminishing behind to the base of the foot. The foot 
is about one-third the length of the body, and is terminated 
by two toes. 
The intestinal tract is of the usual type, a mastax, followed by a 
capacious stomach, and an intestine ending on the dorsal aspect at 
the base of the foot. Gastric glands are seen on both sides of the 
stomach. There is a large translucent ovary, and a large contractile 
vesicle on the ventral side of the base of the foot. The two lateral 
