HiLGENDORF. — Ou Ncw Zealand Eotifera. 117 



tropin is noticeable, as is also their peculiar position, right 

 back in nearly the middle of the body. The stomach and in- 

 testine are consequently very short, though in one case it ap- 

 peared as if the stomach swelled out around and ran forward 

 from the mastax. The most important muscles are those 

 which work the mastax. These are of great size and density, 

 and work against each other. Immediately in front of the 

 mastax is the brain ; it is of fair size, dark, granular, and 

 opaque ; it is semicircular in shape, the diameter of the circle 

 facing forwards. Let into this forward-facing side is a small 

 semicircular eye, concentric with the brain. This is the largest 

 of the eyes, of which there are in all five. The other four are 

 arranged in two pairs very near the front of the head. There 

 is one pair of larger ones, and slightly outwards and forwards 

 from these another pair of much smaller ones. Running 

 forward from the cerebral eye is a double row of bright round 

 spots, about twelve in number, and reaching to the anterior 

 extremity of the body. I cannot guess their use, though it is 

 probably sensory. 



The movements of this Rotifer are very slow. The trophi 

 sometimes work actively, opening very widely from side to 

 side. One specimen had retracted its head and foot (an 

 operation not frequently performed), and so appeared quite 

 round. It was filled with small green bodies, probably de- 

 voured Protozoa. 



Hab. The pool. 



Five or six specimens were observed during the winter. 



Genus Planoventer, gen. nov. 



Generic characteristics : Of great size, never less than 

 ■JLin. Body flattened ventrally, arched dorsally Corona 

 almost quite prone, with only a slightly upward inclination. 

 Foot very indistinct ; toes of fair size. Brain large and dark- 

 coloured. Eye distinct, cervical in position, just in the an- 

 terior part of the brain. Tail and auricles wanting. 



I have tried to put this specimen into nearly every genus 

 of the Notommatadce. The absence of tail and auricles, and 

 the presence of an eye, close to it all genera but Proales 

 and Furcularia. Now, all the Proales hitherto described 

 are small and slight, not large and massive ; the ciliated 

 face is not nearly prone, and the brain is invariably clear. 

 As for the Furcularia, the body is larviform, not pisciform, 

 compressed, not depressed, and the eye when present is 

 always frontal, not cervical. For these reasons I have 

 placed this specimen in a new genus rather than destroy 

 the distinctness of an old genus by forcing an intruder within 

 its ranks. 



