246 Transactions. — Botany . 



It appears to be abundant in Hawke's Bay, at least in one locality. I 

 have not found it in Canterbury. 



This plant at first sight bears great resemblance to S. dejectum, Breb., 

 and indeed, when seen in end view, is not to be distinguished from that 

 plant. But, as Dr. Spencer remarks in his letter to me, the broad junction 

 of the segments in side view renders it distinct. Balfs observes of S. dejec- 

 tum that " its segments are connected either without a band or with a very 

 short one : " the expression of Babenborst is — " sinu amplo, acutangulo vel 

 obtusangulo ; " but no conclusion could be drawn from either phrase that 

 the segments of the European plant are so closely and broadly joined 

 as those of S. clepsydra. Indeed, Balfs gives the breadth at constriction of 

 S. dejectum as ^"hs i ncn > which is much smaller than that of the New Zea- 

 land plant. If S. cuspidatum, which differs from S. dejectum chiefly in the 

 length of its connecting band, is considered a good species, the same rule 

 might well be observed for S. clepsydra. 



S. cuspidatum, Brebisson. (B. XXI.) 



Not common. Two specimens from Canterbury, and a few from 

 Hawke's Bay. 



S. (Didymocladon)furcigerum, Brebisson. S. (R. XXXIII.) 



Fig. 13. 



The specimens which I have seen have all either five or six radiating 

 processes hi end view. Babenhorst unites Didymocladon with Staurastrum, 

 and says that the plant may have 3-4-6-7-8-9 rays : he omits 5. In all 

 my specimens the rays in focus at the extreme end have the other series 

 behind them in exact, or almost exact, correspondence with them, as 

 shown in my figure. 



For comparison with my D. stella (Trans., vol. xiii., p. 308) see below, 

 under that species, in the second part of this paper. 



Only from Hawke's Bay, where it seems to be not uncommon. 

 8. Penium, Brebisson. 



P. margaritaceum, Ehrenberg. (R. XXV. and XXXIII.) 



I have specimens which, I think, can be referred to all the three varie- 

 ties, a, /3 and y of Balfs. Babenhorst unites the two first, and indeed here 

 they all occur mingled together. As for the third, the main difference 

 between it and the others, in England, appears to be the smaller size of 

 its granules. None of my specimens show such large granules as are 

 figured by Balfs, but some are slightly constricted at the middle, while 

 others show no constriction. 



I was fortunate enough to find, on one occasion, a large quantity of 

 this plant in full conjugation, with attached zygospores : there seems to be 

 nothing to distinguish it from the English species. 



