Reviews — Frof. W, C. Williamson on Fossil Plants. 519 



Caradoc. 



L. Llandovery. 



CUmacograptus,DipIoffraptus, Dicranoffraptus, DewJrograptun, Grapto- 

 lithu's (S.M.C. p. 31). 7o-L\zoA:' Berenicea, Fenestella?_ Glauco- 

 nome, Fhyllopora, Ptilodictya, great increase of species (Ibid. 

 p. 44). 

 No Graptolites in S. M. Cat., Climacograptus one sp., Grapfolifes 

 ■priodon, Bronn (Nich. Mono. pp. 97,98). Polyzoa: Fenestella? 

 I Glauconome innexa, Fhyllopora, Ptilodictya. 

 U. Llandovery.' Graptolithus priori on, Bictyonema (S.M.C. p. 69). PoLYZOA: Ftiln- 



j dictya, Fenestella. 

 "Wenlock Shale.: Cladoqraptus, Cyrtograptus, Graptolithus, Retiolites, Bictyonema 

 (S.M.C. p. 81). Polyzoa : Fenestella, Ptilodictya (Stomatopora 

 species, Vine). 

 Graptolithus priodon, Bronn (S.M.C. p. 93), Graptolites colonos, 

 Retiolites, Cyrtograptus, Ptiloqraptus (Fich. p. 98). Polyzoa: 

 great increase of species, see list. 

 Lower Ludlow.^ Bendrograptus, Graptolithus (S.M.C. p. 115). Four species recorded 



i both in Catalogue and the same by Nicholson. 

 Upper Ludlow. Graptolithus sp. recorded (S.M.C. p. 128). 



112, Hill Top, Attercliffe, Sheffield.' 



Errata, etc. 



Page 471 — 3 lines from bottom remove bracket after " sub -order ") and place it 

 after "remains") in line above. 



Page 473 — Between "Branches," and " Conooecium " insert — 

 Dissepiments. " Bars which connect together the branches." 



Wenlock Lime 

 stone. 



I?, E "V I E "W" s. 



I. — On the Okganization of the Fossil Plants of the Coal- 

 measures. Part XI. By Prof. W. C. Williamson, F.R.S. 

 Phil. Traus. Eoy. Soc, Vol. 172, Pt. 2, 1881, p. 283, and Plates 

 47-54. 



THE contributions of Prof. Williamson to the Eoyal Society on 

 the organization of the fossil plants of the Coal-measures have 

 now reached the eleventh, part, which indicates the same amount of 

 labour and is of equal interest and importance as the preceding series. 

 Throughout these researches the author has shown his intimate 

 acquaintance with, the views of both English and foreign writers 

 on the subject, while his study of the recent Cryptogamia, which he 

 has cultivated for the especial purpose of comparison, has been of 

 material importance in these investigations, and although some few 

 points in the structure and affinities of the fossils may be differently 

 interpreted by other palceobotanists, the carefully executed and 

 enlarged figures prepared by himself will be invaluable for the study 

 of coal plants. 



In the present paper the author discusses the opinion of M. 

 Renault on the relation of Sigillaria and Lepidodendron, and after 

 describing some new sections of these plants. Prof. Williamson con- 

 siders there is " a clear proof that, contrary to the conclusions of M. 

 Eenault, age does bring about very important changes in the form 

 and arrangement of the tissues in the branches of these plants." 

 Further, his most recent researches have brought to light another 

 very remarkable series of facts indicating the Lycopodiaceous 



1 My next Report will be " Jurassic Polyzoa." Any help which can be given to me, 

 either by the loan or " gift " of specimens ; any notes of species in different localities ; 

 or help of any sort, will be duly acknowledged, I desire to make the Report as full 

 and exact as possible. — G. R, V. 



