12 Transactions. — Botamj. 



circular end in end-view. He gives its length as only 36 /x, 

 and does not mention E. sinuosu7n. 



■■'• Euastravi longicolle, Nordstedt. Plate I., fig. 7. 



There is in this plant, near the middle of each segment in 

 front-view, a small circular orifice with a spot in the centre, 

 as if there were there a ring-like opening of the frond. Pro- 

 fessor Nordstedt ("N.Z. Alg.," p. 33) casually mentions this 

 feature without further remark. The only other species of 

 this genus, as far as I am aware, exhibiting " scrobiculi " are- 

 E. crassnm, var. scrohiculatum, Lundell, and E. rostratum, 

 Pv,alfs, var. incemorsum, Nordstedt, the former a Swedish, the 

 latter a New Zealand form. 



Eutherford's Swamp, Otaki. 



Euastrum rotundum, sp. nov. Plate I., fig. 8. 



Frond moderate ; constriction deep, linear ; segments in 

 front-view obscurely three-lobed, the basal lobes smoothly and 

 widely rounded, not eniarginate ; on each segment three basal 

 granuliferous inflations, and two others at the ends ; a few 

 granules on the edges. Segments in side-view sub-cylindrical 

 at the base, slightly eniarginate on account of the median 

 inflation, then tapering rapidly towards the ends, which are 

 very slightly dilated. End-view elliptical with median infla- 

 tion. 



Long., 44-6 /a; lat., 26 jx; crass., 17 /x. 



Eutherford's Swamp, Otaki. 



Allied apparently to E. jjingiie, Elfving ; Ijut it is more 

 slender and less clearly three-lobed. It is much smaller and 

 more evenly rounded than E. ansatum, Ealfs. E. obesum, 

 Joshua ("Burm. Desm.," p. 638, and pi. xxhi., 19), is like 

 it in outline, but is larger as a rule, and has apparently no 

 granuliferous inflations. 



'■'■'• Euastrum suhlohatum, Brebisson. Plate I., fig. 9. 



Some authors place this plant under Cosmarium. others 

 under Euastrum. The end-view seems to me to determine its 

 place in the latter genus, and so I leave it. 



Hawke's Bay. 



Euastrum expansum, sp. nov. Plate I., fig. 10. 



Frond very minute, not quite as long as broad ; constric- 

 tion deep, linear, rather wide externally ; segments in front- 

 view three-lobed, basal lobes somewhat protruded and a little 

 turned upwards, end-lobe with concave end but without a 

 terminal notch. Frond in side-view narrow, constriction 

 shallow and wide, segments elliptical towards the base and 

 tapering towards the rounded ends. End-view elliptical at 

 the base, with the tip of the end-lobe appearing as if sub-rect- 



