BY G. I. PLATFAIR. 141 



This is the comiuon Peraneiiui ot our waters. It is, when free-swimming, 

 cuneate, sharp-pointed in front and abruptly truneate behind; one corner is 

 sometimes produced as a pointed tail directed backwards, or a blunt wart-like 

 prominence often bifid and placed to one side. A minute stigma may occasion- 

 ally be observed. Cytoplasm homogeneous and transparent. Neither Stein nor 

 Dujardin describe or figure anything even remotely resembling this fonn. The 

 body is metabolic. 



Per.anema -vsperum, n.sp. (PI. ix., fig. 14). 



Korma corpore globoso; granulis amylaceis ubique asperrima. ^ 

 Long. 15 — 16, lat. 11 — 12^. Rookwood; Lismore (286). 

 A small, irregular, globosa or sul)globose form with the sui'face rugged all 

 over with large irregular amylaceous granules. 



Var. RECTAXGULARE, n.var. (PI. is., fig. 15). 



Forma cylindracea. Dimensiones ut in forma typica. 



Genus Urceolds Meresehowski. 

 Urceolus sabulosus (Stokes) Senn. (PI. ix., fig. 16). 



Syn. Urceolopsis sabulosits Stokes, op. cit. 



Long. 42, lat. 19; lat. oris 13/i. Lismore. 



Hyaline, gi'anular, surface slightly rough, mouth and neck smooth. It 

 glides along applying the huge mouth (which seems to be a kind of open 

 pharynx! to the floecose and sucking in anytliing edible. 



Genus H e t e r o x e ii a ( Duj. ) Stein. 



Heteronema acus Ehr. (PI. ix., fig. 17). 



Long. 30-^90, lat. 3—6^. Auburn (159); Botany; Pott's Hill (121). 

 Flagellum and trailer noted. 



Genus T r o p i u c y p ii u .s Stein. 



Tropidocyphus octocostatcs Stein. (PI. viii., fig. 21). 



I give a side view of an animalcule that may be this species. Stein, T. 

 xxiv., f. 1 — 5; Senn, p. 183. 



Genus X o t o s o L E x u s Stokes. 



NOTOSOLENUS PENTAGONUS, n.Sp. (PI. ix., figs. 2, 3). 



Forma corpore pentagono; f rente acute-rotundata, pone truncata; lateribus 

 emarginatis; angidis rotundatis; vertice visa compressa. 



Long. 21, lat. 17 fi. Lismore (358). 



There are three other species described and figured by Stokes, op. cit., p. 

 108, PI. ii., f. 10 — 14; cf. Senn, p. 183. All forms of the genus are compressed 

 arcuate in end view. This species forms a fairly regular pentagon with the 

 anterior angle somewhat produced ; body truncate behind, widest in the middle ; 

 sides emarginate, angles rounded. Cytoplasm hyaline, finely gi-anular in the 

 centre of the cell, with a phai'ynx-like mark below the flagellum. Stokes also 

 remarks on this. Flagellum thick, straight, a long trailer sometimes present. 



