LEPIDOPHLOIOS, AND ON THE BRITISH SPECIES OF THE GENUS. 547 



structure of the leaf-scars, for the characters derived from the latter afford some of the 

 most important points by which Lepidophloios is separated from Lepidodendron. 



Secondly, in reference to the specimen described by Mr Carruthers, as supporting a 

 similar view, viz., that Halonia was a branch of a true Lepidodendron, the whole evidence 

 afforded by that specimen shows that Mr Carruthers has been mistaken in his observa- 

 tions. This example (PI. II. fig. 8), which is an impression, is in the collection of the 

 British Museum, and while preparing my Catalogue of the Palaeozoic Plants in the 

 Geological Collection, I had every opportunity of carefully examining it, and to ena,ble me 

 to confirm the opinions I then formed of its true relationship, at my request, Dr Henry 

 Woodward, F.P.S., kindly sent me a cast taken from the impression of the specimen. 

 An examination of this cast confirms the description which I gave of the fossil in my 

 Catalogue* The leaf-scars on the specimen are characteristically those of Lepidophloios 

 (PI. II. fig. 8a, 8b), and show conclusively that Halonia is a fruiting branch of Lepido- 

 phloios. Of the two specimens, then, which by British authors have been brought forward 

 to prove that Halonia was the fruiting branch of Lepidodendron, one, owing to its 

 imperfect preservation, gives no evidence in favour of any particular view, while the 

 other is a typical Lepidophloios. 



1891. Cash and Lomax. " On Lepidophloios and Lepidodendron," Report Brit. 



Assoc, for 1890, p. 810. 



Mr Lomax kindly showed me the specimen which was subsequently the subject of 

 this paper. The specimen is a small stem of Lepidophloios — Lepidophloios acerosus, 

 L. and II., sp., I believe — whose internal organisation was preserved, and whose structure 

 was identical with the specimens described by Williamson as Lepidodendron fuliginosum, 

 which therefore must be classed as Lepidophloios. 



1892. Williamson. " On the Organisation of the Fossil Plants of the Coal Measures " 

 (Abstract), Proc. Roy. Soc, London, vol. 50, p. 469. 



This paper, of which only an abstract has as yet been published, deals with many 

 important points on the structure of Halonia and Ulodendron cone-scars, also on the 

 structure of the leaf-cushion and leaf-scar. 



Referring to Halonia and Ulodendron, he mentions that their relationship to each 

 other is " still in a state of serious confusion." He further states that the scars in Ulo- 

 dendron are usually defined as biserial, being arranged in two longitudinal rows, whereas 

 in Halonia the rows are more numerous and the scars quincuncially arranged. 



It is true that confusion appears to exist in the minds of some botanists, regarding 

 the distinctions between " Ulodendron " and " Halonia," but not only do the two so- 

 called genera differ in the arrangement of the cone-scars, but also in the form and structure 

 of the leaf-scar and cushion. Further, as I have pointed out before, Ulodendron 

 does not exist as a genus, but as a condition or state of more than one genus. But even 



* p. 171. 



