56 Transactions. — Zoology. 



Pleuronema cyclidium, sp. nov. Plate V., fig. 16. 



Animalcules siib-reniform, with very shallow groove, about 

 twice as long as broad, having a number of long fine hau'-like 

 setae over the whole body ; seta3 of equal length throughout. 

 Extensile membrane of the oral region narrow, and rather 

 deep when extended. Contractile vesicle single, at one ex- 

 tremity ; nucleus sub-central, elliptical. A number of granular 

 masses often visible in the parenchyma. 



Length, ^ato i^^^h = 19 fi. 



Wellington, A. Brandon. 



Differs from P. chrysalis and P. coronaia in its extremely 

 small size, which was constant in many hundreds of specimens 

 observed, and which would make it approach nearer to Cyclidium 

 or Uronema, except for the absence of the long caudal setge 

 characterizing those genera. 



Genus Cyclidium. 

 Cyclidium glaucoma, Ehrenberg. Wellington. 



Genus Uronema. 

 Uronema marinum, Dujard. Wainui. 



Order Heterotkicha. 

 Genus Metopus. 



Metopu^ sigmoides, Mliller. Wellington. 

 Genus Spirostomum. 



Spirostovium amhiguum, Ehrenberg. Wainui, Hutt Valley. 



Genus Stentor. 



Stentor gracilis, sp. nov. Plate V., Fig. 13 ; a, h. 



Body of moderate size, highly extensile, white or light- 

 brown : when fully extended very slender for almost all its 

 length and suddenly widening to the peristome, giving some- 

 thing of the appearance of a broad-headed nail. Peristome at 

 full extension nearly half as wide as the length of the body. 

 Sides of the extended stem nearly parallel, average width below 

 the peristome region about one-fifteenth of the total length. 

 Parenchyma containing often several dark- coloured granular 

 masses. Contractile vesicle spherical, situated below the peri- 

 stome. Endoplast band-like. Peristome border narrow, slightly 

 emarginate in its whole extent, with a very deep cleft on one side 

 extending for some distance down the stem ; the cleft bears the 

 usual peristomal cilia. Body when free-swimming elongate, 

 racket-shaped, exhibiting the cleft of the peristome almost closed, 

 as a narrow longitudinal slit. 



Length of the extended animalcule rather mo)e than J-^ inch 

 =^ 883 /(. 



Wellington, Hutt Valley, W. F. Barraud. 



