BY G. I. PLATFAIR. 139 



Sphenom».\-as tekbs (Stein) Klebs. (PI. viii., tia:^. 14, 15). 



Syn. Atractonema teres Stein, op. cit., T. sxiii., f. 35 — 41; Clostenema, 

 socialis Stokes, op. cit., p. 112, PI. ii., f. 15. Almost, if not (|uite, a,s common as 

 the foregoing species. Senn, I.e.. \k 177, f. 128d, figures it with only an in- 

 ciiiient trailer (the secondary fiagelhim), but I find specimens with a trailer 

 twice the length of the body, and young forms have no second fiagellum at all. 

 The fact is that the trailer develops later than the true flagelluni. The latter 

 is of the Peraiiema-type, stout at the ba,-;e and tailing dtf to tlie tip. It is 

 held motionless for tlie most part, straight out in front; only the tip is in 

 movement. Sometimes the extreme end of the cell is constricted into a little 

 stubby tail. 



Long. 20—25, lat. (i— 12^. Auburn (139); Lismore (298, 312. 345). 



Var. PYRIPORMI.S, n.var. (PI. viii., tigs. 16, 17). 



Cellulae ut in f. typica rugis nullis, sed pyriformibus, interdum cauda brcvi 

 subtriangulari instructae. 



Long. l(i— 2(i, hit. 9—20^. Auburn (140); Botanv (91); Lismore (188, 

 298, 312). 



Smooth and without ri<Iges a.s in the typical form, but in siiape pyriform, 

 with or without a short broad tail. 



It is probable that S)ih. teref is a young form or at least a polymorphic 

 form of Sph. auMralin. I have noted faint longitudinal lines down 

 the body, which seemeil to indicate the formation of ridges. In PI. viii.. fig. 18, 

 is shown an intermediate form in wliich the ridges are plainly visible, but the 

 characteristic marginal granulation was n<]t present and the cell therefore in- 

 clined to Sph. teres. 



SpHENOMONAS TRIQUETRA, n.sp. (PI. viii., fig. 20). 



Cellulae inaequaliter ovatae, utro(|ue polo acuminatae; a vertice visae in- 

 aei(ualit*r triijuetrae. 



Long. 30, lat. 20^. Kookwood; Botanic Gardens (156). 



In-egularly ovate in shape, pointed at each end, with a ridge running spir- 

 ally down the face; end view irregularly triangular with hollow sides and rounded 

 angles. 



Var. CUNEATA, n.var. (PL viii., fig. 19). 



Cellulae inaequaliter euneata, fronte rotundatae, postice attenuatae, acumina- 

 tae; a vertice visae inaefpialiter triquetrae. 



Long. 30, lat. Ibf,^ Guildford. 



Somewhat cuneate in shape, broadest in front, where it is rounded off, 

 gradually narrowed to a subacute point bcliind. A longitudinal ridge down the 

 face; end view irregularly triangular with hollow sides and rounded angles. 



Sphenomonas excavata, n.sp. (PI. ix., fig. 1). 



Cellulae oblongae, subreetangulares ; extremitatibus lateribusque arcuatis; 

 utroque polo bulla conica praeditae ; rugis 3, mediano spirale, per longitudinem 

 dispositis instructae; fiagello recto. A vertice visae subreetangulares, utrinque 

 rugis altis 3. A latere late-fusiformes. 



Long. 32. lat. 21, crass, c. 10^. Lismore (358). 



Subreetangular, ends and sides arched; at each pole a conical boss, from 

 the anterior part of wliich the straight thick Peranema fiagellum springs. No 



