394 Transactions. — Geology. 



structions of man. It was, moreover, from this place that 

 Sir Juhus von Haast obtained the collection of plant-remains 

 sent to Europe for identification. 



The place has therefore claims to be considered a typical 

 locality, and, but for the doubt that still remains as to the age 

 of the Mount Potts shell beds at Eocky Gully, I should have 

 preferred to designate this group of beds the " Mount Potis 

 plant beds," instead of " Nugget Point plant beds." 



The Nugget Point beds form the long narrow promontory 

 on which the lighthouse stands, and the outlying rocky islets. 

 They are followed conformably by the Spirlferina beds. The 

 dip of the beds is to seaward, and consequently the lowest 

 beds of the series are not seen. The thickness exposed to 

 view at low water is about 350 ft. 



Sir James Hector identified among the plant-remains 

 collected by Mr. McKay at Hunt's farm, in Eighty-eight 

 Valley, Glossojjteris, Zamites, and Bhacop)iyUum.''' 



Among the plant-remains from Tank Gully, Mount Potts, 

 Baron Von Ettingshausen determined Taniopteris psendo- 

 vittata, Asplenium hochstetteri, Palissya podocarpiodes, Baiera 

 australis, and others, all more or less related to European 

 Triassic forms. f 



The form from Mount Potts identified by Sir James 

 Hector as Glossopteris was determined by Ettingshausen 

 to be Tceniopteris, and probably the Nelson Glossopteris 

 also belongs to that genus. 



(e.) Spiriferina Beds. — These embrace the lowest marine 

 beds of the Hokonui system. Among the fossil shells found 

 in them at Nelson, Nugget Point, and Hokonui Hills are 

 Spiriferina, three sp., including the new sub-genus Psioidea,\ 

 created by Sir James Hector to embrace a small distinctive 

 form resembling Spiriferina cristata, Schloth.; and Epitiiyris, 

 Rhynchonella, and Pletorotomaria. 



The long-winged species of Spiriferina found in these beds 

 at Nugget Point, Hokonui, and Mount Potts have been re- 

 ferred by the Geological Survey to the genus Trigonotreta of 

 Konig.§ 



(d.) Halobia lommeli Beds. — The principal forms in this 

 liorizon are Halobia lommeli, Wissm., Nuculana, Retzia, 

 Ejnthyris, and rsioidea. 



The evidence as to the age of the Mount Potts beds is, 

 unfortunately, not very satisfactory; l)ut the presence of Halo- 

 bia lommeli, of bones supposed to belong to Ichthyosaurus, 

 and the apparent absence of true Spirifera seem to correlate 



* Hector, " Outline of New Zealaud Geology," 1886, p. 74. 



t Trans. N.Z. Inst., vol. xxiii., p. 237. 



J Trans. N.Z. Inst., vol. xi., p. 537. 



§ Hector, " Outline of New Zealand Geology," 1886, p. 75. 



