Kirk. — On Dicksonia antarctica and D. lanata. 345 



Nephrodium thelypteris, Desv., var. squamulosum. — E-otomahana affords the 



most southern locality yet recorded. 

 N. unitum. Br. — Certainly the most abundant of the tropical ferns which owe 



their existence in New Zealand to the inJ&uence of hot springs ; northern 



and eastern limit about hot springs at Maketu — on the authority of 



Captain Mair j Rotomahana, in immense profusion j Otumakokori, near 



Tapuaeharuru, and Waipihi, which is the most southern locality known 



to me, although it doubtless is found about the hot springs at the south 



of Lake Taupo. 

 Nephrolepis cordifolia, Baker. — Otumakokori, abundant. Captain Mair 



informed me that it had been found near Tapuaeharuru, but I failed to 



detect it in that locality. 

 Polypodium rupestre, Br. — Summit of Tarawera, 3,600 feet. 

 Schizcea dichotoma, Swartz. — Attains its southern limit at Orakeikorako, in 



the modified temperature of hot springs. 

 Lycopodium selago, L. — Attains its northern limit at Motukino ; first recorded 



locality in the North Island. 

 L. densum, Lab. — Abundant near Kaitiriria ; not observed further south. 

 L. cernuum^ L. — Everywhere abundant about hot springs. 

 L. clavatum, L., var. magellanicum. — ^Attains its northern limit on the high 



land north of Botorua. 

 L. voluhile, Forst. — Ascends to 2,800 feet on Tarawera mountain. 

 Tmesipteris forsteri, Endl. — Summit of Tarawera mountain; epiphytic and 



terrestrial. 

 Psilotum triquetrunb, Swartz. — Attains its southern limit at Orakeikorako. 

 Isoetes kirkii, A. Braun. — Botokakahi ; the most southern habitat yet 



discovered. 



Art. XLIII. — On the Specific Characters of Dicksonia antarctica, Br., and 

 Dicksonia lanata, Col. By T. Kirk, F.L.S. 



[Read before the Auckland Institute, 14:th October, 1872.] 



The characters presented by Dicksonia antarctica and D. lanata in these 

 islands are so remarkably constant and so easily recognized, owing to the 

 absence of intermediate forms, that it seems desirable to inquire if their union, 

 under the name of Dicksonia antarctica, can be maintained. I must confess 

 at the outset that it is with the greatest difiidence I venture to dissent from 

 the opinion of so high an authority as the late Sir William Hooker, but after 

 a careful examination of both forms in a recent condition, and in many 

 localities, it appears to me that a student unacquainted with either would fail 



T 1 



