MASKELii. — 0)1 New Zealand Desmidiese. 7 



connatum, Limdell. Nordstedt observes that the spines m his 

 specimens do not diverge as much as shown in my figures. I 

 have since re-examined my specimens, and find that in the 

 majority the spines, if produced inwards, would meet exactly 

 at the middle of the isthmus, as in my pi. xxiv., fig. 12a: a 

 few of them are less divergent, as in my fig. 12&. 



Docidium dilatatum (vol. xiii.) is D. ovatmii, Nordst. (" Desm. 

 Brasil."), now attached to the sub-genus Plczirotcsniuvi. The 

 measurement given in my paper of 1880, " length, -Jg-in.," is 

 a clerical error ; it should have been " g^fjin." 



Triploccras tridcntatum (vol. xiii.) ; the same, var. cylindri- 

 ciim (vol. XV.); the same, var. siiperhiun (vol. xviii.). The dis- 

 tinctions upon which I based this new species and its variations, 

 a,s separating it from T. verticiUatum and T. gracile, Bailey, 

 from T. pristida, Hobson, and T. gracile, Archer, were the 

 presence of three denticulatious on the terminal processes and 

 two tricuspidate projections just below^ them. Professor 

 Nordstedt considers the last as accidental. On re-examining 

 my specimens of var. cylindricum I find that some have the 

 projections, others have not ; consequently these cannot be 

 used as sufficient distinction. Nordstedt attaches my var. 

 superhum to T. verticiUatum, and my var. cylindriciim to T. 

 gracile, Bailey ; but he says that in neither has he been able 

 to see the terminal processes tridentate. In all of the eighteen 

 specimens I have preserved of both, the three teeth are very 

 distinct and clear, although in some which are slightly turned 

 towards the eye the third tooth is seen only foreshortened. 

 There is indeed a marked difference between these two plants 

 and T. aculeatiimor T. bidentatian, Nordst. ("N.Z. Alg.," p. 64), 

 of which I have also specimens. In these last tlie terminal 

 teeth are never, as far as I have seen, more than two, and 

 sometimes only one is visible. Of the original T. tridcntatum 

 I have unfortunately no specimens now, and the locality 

 where it was gathered is no longer available. It will be worth 

 while for some one to make a thorough examination of the 

 plants of this genus in New Zealand, for they are very beautiful 

 and worthy of full investigation. On the whole, I venture to 

 maintain my original diagnosis ; and, if T. verticillatuin and 

 T. gracile never have three terminal denticulatious, I think 

 my plants are rightly separated from both. 



The localities in New Zealand where Dr. Berggren col- 

 lected Algce appear to have been very numerous, ranging from 

 the Bluff to the Bay of Islands. I do not see, however, in the 

 list given in Professor Nordstedt's paper any places in Hawke's 

 Bay or on the south-western coast of the North Island. Most 

 of the new species and varieties mentioned in this present 

 paper and former papers of mine have been collected in these 



