14 Transactions. — Botany. 



the segments taper with sinuous edges to the rounded ends. 

 End-view sub-elhptical with mediaai inflation. Cytioderin 

 very obscurely punctate, if not free from puncta. 



Long., 38-6 /x ; lat., 22-7 /x ; crass., 13-5 /x. 



Hawke's Bay. 



E. incrassatnm, Nordst., is more elliptical, and has not 

 dilated ends ; also its crenations are not equal. E. crenatinn, 

 Kiitzing, seems near it ; but Dr. Bennett (" Journ. Eoy. 

 Micros. Soc," 1886, p. 9) describes that plant as having 

 quite straight ends and scarcely any notch ; also a very 

 shallow constriction. It differs from E. dcnticulatum in 

 the absence of the rather deep notch which in that species 

 separates the terminal from the lateral lobes. In E. undulo- 

 swm the edge is evenly crenulate from the constriction to the 

 terminal angles. 



Euastrum irregulare, sp. nov. Plate II., fig. 14. 



Frond small ; constriction deep, linear ; segments in front- 

 view sub-trapezoidal, the sides tapering from the base to the 

 rather wide ends ; ends emarginate, with conspicuous notch, 

 tlie lips of which do not protrude ; at the angles fine spines ; 

 sides irregularly emarginate, incised with small but distinct 

 depressions, but the division between the terminal and. lateral 

 lobes is not clearly marked. Inflations on each segment in 

 front-view seven — three at the base, two at the end, and two 

 near the sides. In side-view the segments are sub-rectangular, 

 slightly inflated towards the base, the ends very slightly 

 dilated, with rounded angles. End-view sub-fusiform, with 

 sinuous edges. 



Long., 22-3/x; lat., 18/x; crass., 8-9 /x. 



Kaitoke ; Otaki ; Masterton. 



In outline this plant is similar to some varieties of E. 

 hinale, except that the edges are much more irregularly 

 incised ; the rmmber and arrangement of the inflations also 

 differentiate it. 



Genus Cosmarium, Corda. 



Cosmarium variabile, sp. nov. Plate II., fig. 15. 



Frond moderate, elongated ; constriction shallow, rather 

 open ; segments tapering from rounded basal angles to rather 

 wide truncate ends ; sides sometimes convex, sometimes 

 straiglit, sometimes concave ; ends very slightly rounded or 

 "almost straight, never concave, but with often the inner cell- 

 wall distinctly thickened. The cytioderm is not punctate. 

 In side-view segments elliptical, ends more or less acute, sides 

 smooth. The end-view is elliptical. 



Long., 42 /x ; lat., 21 /x ; crass., 15 /x. 



Hawke's Bay ; Otaki. 



