Maskell. — On Nciu Zealand Desmidiese. 17 



Cosynarium regncsi, Eeinsch, var. ornafiim, var. nov. 

 Plate II., fig. 25. 



Frond very minute ; constriction shallow, wide, and curvi- 

 linear ; segments in front-view irregular, sides very short, cut 

 into three minute lobules with concave edges ; angles between 

 the lobules sharp ; ends concave. Cytioderm bearing at each 

 side of each segment three granules arranged triangularly. 

 Segments in side-view sub- fusiform, tapering gradually to 

 rounded ends ; two minute granules visible on the face and 

 two others on each edge : of the last, one pair are near the 

 base, the other near the end. End-view angular-elliptical, a 

 minute gi-anule marking each quasi-angle. 



Long., 9/x; lat., 9fx; crass., 2-5^. 



Christchurch. 



If I may judge by a tracing sent to me by Mr. "W. B. 

 Turner of Eeinsch's original figure of this plant, and by a 

 figure of Mr. Turner's in the " Naturalist," February, 1886, 

 the plant herein described is more ornate than the original. 

 Some specimens, however, in slides sent me from England a 

 few years ago by Mr. Joshua, are nearer to this New Zealand 

 form, though not exactly similar. Reinsch's figure is, as I 

 understand, by no means a good one. The plant is exceed- 

 ingly minute, and is scarcely to be made out with a less 

 power than 1,000 diameters. It appears to have sonietimes a 

 pink tinge. 



Cosmarium hohniense, Lundell, forma viinor. Plate III., 

 fig. 26. 



Long., ol/t; lat., 3o/x; crass., 23 7 /x. 



Hawke's Bay. 



Shorter, and not quite as wide as the original type. The 

 American form (Wolle, " Desm. of U.S.," p. 68) is even nar- 

 rower. The dimensions here given are constant in many 

 specimens. 



Cosmarium naegeliamun, Brebisson, var. lation, var. nov. 

 Plate III., fig. 27. 



Frond small ; constriction deep, linear, narrowed at the 

 mouth ; segments in front-view nearly twice as wide as long, 

 with slightly convergent sides ; edges crenulate, with five cre- 

 nations at each side ; ends wide, j)lane, or very obscurely 

 crenulated. In side-view, segments sub-rectangular, angles 

 rounded ; in end-view eUiptical, with a very slight median 

 inflation and an obscurely crenulate edge. Cytioderm minutely 

 punctate, the puncta obscurely arranged in transverse rows 

 when in side-view. Zygospore globose, spinous with short 

 sharp subulate spines. 



Long., 25 /x; lat., 23-8 yu.; crass., 11 jj-; diam. zygosp. 

 incl. spin., 32-7 /x; long, spin., 3/x. 



