Maskell.— 0/i Neio Zealand Desmidieae. 23 



I have proposed tliis as a true " variety " of the original 

 form, as in all the specimens seen since 1879 (perhaps more 

 than a hmidred) the twisting of the frond, although distinct, 

 is never sufficient to bring the angles in end-view regularly 

 alternate as in the European and American types. 



Staurastrum striolatum, Naegeli, var. acutius, var. nov. 

 Plate IV., fig. 39. 



Angles, both in front- and end-views, a good deal sharper 

 than in the type. 



Long., 21 /A ; lat., 23 /x. 



Hawke's Bay. 



Staurastrum ventricosum, sp. nov. Plate IV., fig. 40. 



Frond moderate ; constriction deep and wide ; segments ia 

 front view elliptico-fusiform, wuth convex ends, and prolonged 

 into short processes each tipped with three minute spines ; 

 cytioderm rough with conspicuous granules ; on the outer 

 edges several spines, small, simple, neither dilated nor forked. 

 End-view' triangular ; processes short ; edges obscurely irregu- 

 lar ; sides slightly concave ; granules in transverse series. 



Long., 39 /x; lat., 40 /a. 



Christchurch ; Wellington; Kaitoke ; Hawke's Bay. 



A plant which I had at first considered as a variety of -S'. 

 proboscideum, Brebisson ; but it is separated from that species 

 by the absence of forked or dilated spines, and by the trans- 

 verse arrangement of the granu.les in end-view. It is much 

 smaller than the next species, and has not concave or de- 

 pressed ends with widely divergent spines in front-view. 



Staurastrum splendidmn, sp. nov. Plate IV., fig. 41. 



Frond rather large ; constriction wide. Segments in front- 

 view sub-orbicular, the ends depressed or sometimes slightly 

 concave, sides produced into moderately long processes, each 

 bearing three conspicuous spines. Cytioderm rough with 

 large conspicuous granules. Edge smooth, or obscurely 

 irregular for a little way from the isthmus, thence conspicu- 

 ously crenulated to the commencement of the depressed ends ; 

 between the crenulations conspicuous simple spines inclined 

 outwards. End-view triangular ; cytioderm rough with 

 granules arranged transversely ; sides slightly concave ; edges 

 crenulate, with simple spines ; angles truncate, tricuspid ; 

 viewed from the isthmus the orbicular form of the segment is 

 conspicuous. 



Long., 67 /a; lat., 52 /x. 



Christchurch ; Hawke's Bay. 



This is the plant which in my paper of 1882 I wrongly 

 considered as a form of .S'. aculeatum, Ehr. Mr. W. B. Turner 

 tells me that he thinks it is intermediate between the smaller 



