548 PLANKTON OF THE SYDNEY AVATER-SUPPLY, 



non-vibratile setose hairs. This shows that M . litomesa is a 

 form of J/, riosslii Pei'ty, which I have often found quite 

 devoid of hairs. M . splendens is never crenulate, though the 

 edge appears somewhat irregular owing to the criss-ci'oss 

 furrows, and the setae are distinctly spinous. 



Chlamydomonas intermedia Chodat. (PL Ivii., f.l4). 

 Coenob. diam. 53; cell. long. 13, lat. 10 /x. 



Chlamydomonas sp. (PI. Ivii., f.l5). 



Coenob. diam. 38; cell. long. 12, lat. 7 /x. 



This coenobium was peculiar in being disciform — the cells 

 all on the same plane. I am of opinion that Gleoc.ystis and 

 Sphcerocystis are young, vegetative stages of C hlatn ydonionas . 



CoTHURNiA amphorella Maskell, Trans. N.Z. Inst., 1887. 



Long. 75-90 ; lat. max. 30-34 ; lat. or. 16-24 /x. 



The foot is an extension of the body-plasma through a 

 minute orifice at the hinder end. If the organism, while 

 young, chances to get fixed on its side, it can form no pedicel. 

 In this condition, it seems to be the same as Platycola decum- 

 bens Ehr. The lorica is, at first, pale straw colour, but 

 changes with age to a deep red-brown. (PI. Ivii., f.20,21). 



RHIZOPODA. 



Pelomyxa palustris Greef var. echinulata, n.var. 



(PI. Ivii., f. 16,17). 



Forma matura, oblonga, setis spinosis curvatis brevibus dense 

 obtecta. 



Long, ad 100; iat. ad 40-50; spin. long, ad 20 /x. 



Obtained from the pond at Pott's Hill, and the tank in 

 the Botanic Gardens. Smaller specimens, without spines, 

 were obsei'ved in the same water. Some were noted, also, 

 with the spines very faint, of a mucous character, only notice- 

 able on close observation. 



