HiLGENDOKF. — Oil Ne2v Zealand Eotifera. 113 



is a dorsal seuse-orgau ; it is of good size, bears a tuft of setae, 

 and is capable of being erected and depressed. 



Rotifer macrurus is viviparous. In examining a specimen 

 I was greatly puzzled by the appearance of two small faint 

 eyes away back in the posterior part of the body, and also by 

 the appearance of two small trophi, which moved slightly 

 while I was watching them. It was not for a long time that 

 I discovered that these appearances were due to the presence 

 of a young Eotifer with the body of its parent. The fcetus 

 was bent round upon itself, and moved freely within the space 

 at its disposal. It turned completely round several times, 

 now having its head directed forwards, and now backwards. 

 It was perhaps half as long as its parent, but much more 

 slender even proportionately. 



Movement, typically Bdelloidan. The hold with the foot is 

 taken quite beside the hold with the head, so that the Eotifer 

 travels fully its own length at every loop. I never saw it 

 swim with its ciliary wreath. Its motions were usually lively, 

 a period of creeping being alternated with one of feeding ; 

 but at times it would lie wholly retracted into an almost 

 spherical ball. This was the usual attitude taken when death 

 was approaching, but one specimen remained fully extended, 

 and curled its foot up, just as a pig's tail is curled. 



Hah. Among Algte allied to Spirogyra. In small pools. 

 Fairly plentiful. 



Genus Callidina, Ehrenberg. 

 Generic characters : Eyes absent. 



II. Callidina quadridens, sp. nov. Plate VIII., figs, ii., ii.a. 



Specific characters : Body plump and fluted distinctly, but 

 not closely. Foot very slender. Ciliary wreath projecting 

 forward in two sharp prominences. Teeth, 4. 



No colour. Its general shape is long and slender, more so 

 than H. macrurus. Its body, however, shows some plumpness 

 as compared with its long head and foot. This latter is very 

 slender, and contains about six telescopic joints. The head is 

 very long, the neck part of it being transversely wrinkled. It 

 is when the anterior part of the head is retracted and the 

 corona expanded that one of the differences between this 

 species and other Callidinas is seen. Instead of the corona 

 consisting of two broad lobes, lined by a sinuous wreath of 

 cilia, there are two very narrow projecting lobes, very much 

 narrower than the rest of the body. The longitudinal flutings 

 of the body were very distinctly marked. The mouth is in 

 the ventral centre of the corona. Just within it, on each side 

 •of the gullet, are two very distinct bean-shaped glands. These 

 8 



