Laing. — On the Algce of New Zealand. 299 



even if comparatively rare or sporadic, whereas both Scaberia 

 and Phyllospora are stated to be common in the Handbook, 

 although no precise locality is given. *Lessonia fuscescens I 

 have dealt with elsewhere. After excluding such intruders 

 we find Agardh and Hooker in practical agreement as to our 

 Phaophycece , which we may' now say are comparatively well 

 known. The chief points of difference still remaining are the 

 introduction by Agardh of two previously unknown species 

 of Elachista and four new Cysiophorce, making his list of 

 Phaophycece fifty-three, while Hooker's stands at fifty-eight. 

 Further alterations will no doubt be chiefly towards a better 

 discrimination of species and varieties. This is wanted 

 especially in the genera Garpophyllum and Echlonia, and 

 probably also in Cystophora. 



On turning to the Chlorophycece we find thirty-seven in 

 Hooker, of which, however, several belong to fresh water. 

 Agardh has only twenty-four, and of these only two are new. 

 He has rejected, therefore, about fifteen of Hooker's species. 

 Of these, several are fresh-water plants ; but on excluding 

 these there still remain about eight species which do not 

 occur in Agardh's list. These are either varieties of recognized 

 forms or minute plants belonging to the lower orders. I have, 

 however, seen several minute Chlorophycecp which I could 

 not assign to any of x\gardh's species. It may be regarded as 

 certain that some small green seaweeds still remain to be dis- 

 covered. I have here, and throughout the paper, omitted the 

 Protopliyceie from consideration, as they are but little known. 



On turning to the Bliodophycece, we find the divergences 

 existing between the two authorities are very numerous. 

 Many of them of course are only differences of classification 

 due to our increased knowledge of the methods of repro- 

 duction ; many others are differences in synonyms ; but when 

 these are eliminated there still remain a large number to be 

 accounted for. Thirty-five new T species have been added by 

 the recent writer. As the total number in his list is 195, on 

 allowing for the Corallines we find he has evidently excluded 

 about fifty of Hooker's species. Again, it may be remarked that 

 it is difficult to give the exact number, as it is not always 

 possible to trace the correspondence of specimens under 

 different names, and as many of Agardh's identifications of 

 Harvey's species are marked with a (?). It would not serve 

 any useful purpose at present to investigate in detail the 

 points of difference between them, as it would be impossible 

 in many cases, without access to type specimens, to form an 

 independent judgment about the point at issue. What I wish 

 to do is to determine within what possible limits of error our 



* Trans. N.Z. Inst., vol. xxvi., p. 304. 



