Maskell. — Ou Neiv Zealand Desmidieoe. 19 



and certainly the number of small crennlations on the margin 

 is about double that of Luudell's plant, which has only twelve. 

 The rather widely-gaping constriction (from which I took my 

 former name) seems to separate it from any species hitherto 

 described. 



Long., 51 jx; lat., 46-49 jx; crass., 16 /x. 



Sumner Eoad, Lyttelton. 



Cosmarium heliosporum, sp. nov. Plate III., fig. 30. 



Frond small ; segments in front-view sub-quadrate, crenate, 

 with from ten to twelve conspicuous crenations ; angles 

 rounded ; cytioderm marked with large granular inflations 

 corresponding to the crenations and radiating from the median 

 space, giving the frond a deeply-grooved appearance ; in the 

 median space, at the base of each segment, a row of small, 

 apparently vertical inflations, usually five in each row. In 

 side-view, segments sub-quadrate, slightly tapering to the wide 

 ends, which are a little convex ; edges smooth at the base of 

 the segments, and minutely crenulate at the ends. End-view 

 elhptical, with transverse rows of granules ; viewed from the 

 base of a segment the granules form a circle round the 

 isthmus. Zygospore globose, with numerous spines ; the 

 spines subulate, on broad bases, and minutely divided at the 

 apex. 



Long., 28-3 /x; lat., 23 /x; crass., 15-6 /x,; diam. zygosp. 

 exclus. spin., 33 /x ; long, spin., S-5 jx. 



Hawke's Bay. 



A species belonging to the series of C. crenatum, but dis- 

 tinct by its sub-quadrate segments, wliich are conspicuously 

 crenate at the ends, and by the form and size of the spines on 

 the zygospore. From these spines Mr. Turner suggested to 

 me the specific name which I have herein adopted. 



* Cosmarium amplum, Nordstedt. Plate III., fig. 31. 



I give a figure of this plant, partly because of its peculiar 

 end-view in some cases (roundly triangular) ; partly because 

 the granules seem to me often to be arranged in concentric 

 curves, and not always in quincunx, as Professor Nordstedt 

 reports ; and partly on account of a conspicuous inflation 

 observed in some specimens when viewed neither in front nor 

 directly from the end. The plant is a fine one. Perhaps two- 

 thirds of the specimens observed by me from Otaki have a 

 triangular end-view ; all those from Hawke's Bay have 

 elliptical ends. 



Hawke's Bay; Otaki. 



Cosmarium quadrifarium, Lundell, var. gemmulatum, var. 

 nov. Plate III., fig. 32. 



Frond moderate ; constriction deep, linear ; segments in 

 2 



