Geological Society of London. 235 



The aoithor further stated that Presl's genus Bergeria is Carboniferous, and not 

 Devonian, and that it has no special affinity with Leptophlceum or LepidopJdoios, and 

 he objected to the revival of the name Bergeria. 



Discussion. — Mr. Carruthers observed that, in investigating the plants submitted to 

 him by Mr. Daintree, he eould only deal with published observations and drawings in 

 correlating them with known forms. He considered that each systematic worker Avas 

 at liberty to review the conclusions of previous authors ; and if he saw reasons for 

 doing so, to treat their names as synonymous. In Lepidodendron nothum of linger 

 the leaves are unknown, but the leaf-scars are rhombic, and the decorticated portion 

 of the stem is marked with oval vascular scars. Principal Dawson, in his Lepido- 

 dendron Gaspianum, figures two kinds of leaves, one short and erect, the other 

 longer and outward-curved ; and he shows the external leaf-scars to be rhombic, and 

 the decorticated condition to have oval markings, both exactly as in L. nothum of 

 linger. No foliage or fruits of Leptophlceum rhombicum have ever been figured by 

 Principal Dawson, except as a restoration ; and as these were entirely omitted in his 

 last work, which includes the results of his researches, Mr. Carruthers had determined 

 its identity with Ilnger's L. nothum from the form of the scars, the only characters 

 given in the published figures, or supplied now by the photographs exhibited. Mr . 

 Daintree's specimens put it beyond all doubt that the supposed Ste7-nbergia-^\ih., on 

 which Principal Dawson apparently founded his genus, was merely the undeveloped 

 portion of the apex of the branch. Mr. Carruthers disputed the characters given as 

 being insufficient to distinguish the plants as species, much less to justify their being 

 placed in diff'erent genera. Length or shortness is obviously accidental to the fossil 

 fragments ; and their stoutness or slenderness is due to the part of the branch to 

 which they originally belonged. The leaf-scars are not elongate and lanceolate, but 

 •rhombic in Principal Dawson's figures of his L. Gaspianum ; and if his drawings are 

 right, the description of the leaves as outward-curved must be wrong. No value can 

 be attached to the position of a vascular bundle, which Dr. Dawson says is some- 

 times in the middle of the leaf-scar in the one plant, and always in th-e middle in the 

 other, or to the fact (if it be one) that the internal structure in the one is known, 

 and in the other is unknown. 



Mr. Etheridge corroborated Mr. Carruthers's views as to the identity of the three 

 forms. He thought that the representations given by Mr. Daintree were superior as 

 regards accuracy to those givaji by Prof. Dawson. He pointed out that at the end of 

 branches, where the scars were crowded together, it was almost impossible to dis- 

 tinguish the arrangement ; and he considered that half the species of Lepidodendra 

 BOW in our catalogues would on further examination prove to have had no real 

 existence. We had only to look at a recent tree-fern to recognize the difficulty of 

 idi-awing specific determinations from small or imperfectly preserved specimens. 



The Chairman remarked that the Society were always glad to receive communica- 

 tions from Prof. Dawson, although, of course, there might be a difference of opinion 

 on the subject of such obscure fossils as those under consideration, and he trusted 

 that a question of such importance might be fairly discussed until a definite con- 

 clusion was arrived at. 



II.— March 26th, 1873.— His Grace the Dake of Argyll, K.T., F.E.S., President, 

 in the Chair. — The following communications were read: — 1. "Synopsis of the 

 Younger Formations of New Zealand." By Capt. F. W. Hutton, F.G.S., of the 

 Geological Survey of New Zealand. 



In this paper the author gave a summary of the Tertiary and later Secondary for- 

 mations of New Zealand. He stated that he had been able to determine 375 species 

 of true MoUusca, 12 of Brachiopoda, and 18 of Echinodermata from the Tertiaries ; 

 and under each of the formations which he recognizes he gave the number of species 

 of true Mollusca found in it, indicating the number of recent species, and of those 

 belonging to other formations occurring in each. He also noticed the range and 

 distribution of the various formations.. The Tertiary groups of strata distinguished 

 by the author are, in descending order, as follows : — I. Pleistocene. II. Pliocene : 

 1. the Newer Pliocene or Whanganui group; 2, the Older Pliocene or Lignite group. 

 III. Miocene: 3, Upper or Arvatere group; 4, Lower or Kanieri group. IV. 

 Oligoeene : 5, Upper or Hawke's Bay group ; 6, Lower or Waitewata group. 

 V. Eocene : 7, Upper or Ototara group ; 8, Lower or Brown Coal group. As 

 belonging to the Mesozoic series, the author also described beds of Danian age, under 



