1873.] dawsOn — LErTornicEtrM: khombicuji etc. 371 



LejptophJoeum rhombicum have ever been figured by Principal Dawson, 

 except as a restoration ; and as these Avere entirely omitted in his 

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

 had determined its identity with Finger's L. noilmm from the form 

 of the scars — the only characters given in the published figures, or 

 supplied now by the photographs exhibited. Mr. Daintree's speci- 

 mens put it beyond, all doubt that the supposed Stemberyia-])\\h, 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 different 

 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 sometimes in the middle of the leaf-scar in the 

 one plant, and always in the 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. Etheeidge 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 

 given by Prof. Dawson. He pointed out that at the end of branches 

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

 distinguish the arrangement ; and he considered that half the spe- 

 cies of Lepidodendra now in our catalogues would on further exa- 

 mination prove to have had no real existence. We had only to look 

 at a recent tree fern to recognize the difficulty of drawing specific 

 determinations from small or imperfectly preserved specimens. 



Mr. Peesxwich remarked that the Society were always glad to 

 receive communications 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. 



Makch 26, 1873. 



The Ttcv. Edward Hale, M.A., Assistant-Master at Eton College ; 

 William Cibb, Esq., Aberdeen; John Bcrgcr Spencc, Esq., 75 Mark 

 Lane, E.C. ; Frederic W. North, Esq., of liowley-Hall Colliery, 

 Dudley; John A. Coombs, Esq., C.E., London Gas-Works, Nine 

 Elms, S.W. ; and AVilliam Kingdon Clifford, Esq., M.A., Fellow of 

 Trinity College, Cambridge, and Professor of Applied Mathematics 

 at University College, London, were elected Fellows of the Society. 



The following communications were read : — 



