W. Carruthers — Halonia and Lepidodendran. 147 



which the name LepidopMoios lepidophyllifoUum, Goldenb., is given, 

 are the foliage of the same plant. There can be no doubt as to the 

 fossil on which he founded his genus Cyclocladia ^ being an imper- 

 fectly preserved Halonia. As Goldenberg did not observe any scar 

 at the apex of the tubercles in his specimen of Halonia, this rounded 

 scar, which is very obvious in the fragment called by him Cyclocladia, 

 is made the principal distinctive character of the supposed new genus. 



Eichwald has figured, in his "Lethgea Eossica," (1860), a re- 

 markably fine specimen of a bifurcating branch of Halonia 

 regularis, Lindl. and Hutt., showing on the amorphous cast which 

 fills the cavity the two sets of scars, and in the mould in the rock 

 exhibiting in a very perfect condition the rhomboid marking of the 

 bases of the leaves. The larger tubercles he figures and describes 

 (vol. i., p. 149) as being composed of six to eight smaller ones, 

 arranged together in a radiating manner, and having an open pore in 

 the centre, through which passed the vascular bundle, to the leaves 

 wliich Eichwald supposed wei'e borne only on the large tubercles. 

 The smaller tubercles, which are symmetrically arranged globular 

 swellings on the internal cast, were not noticed by Eichwald to have 

 any indications of the vascular bundle which passed through them. 

 The rhomboidal scars so well marked on the mould in the rock 

 he considers to have supported scales which densely covered the 

 whole surface of the stem. In placing the genus in the Lepido- 

 dendrecB, he distinguishes it from Lepidodendron by its having the 

 leaves placed upon large tubercles. 



In a memoir on the Coal-plants of Westphalia, published in the 

 eighteenth volume of Dunker's " Palaeontographica," (1868), Von 

 Eoehl supposes that the tubercles may have supported fruits ; and 

 this view is also adopted by Schi/mper as the interpretation of the 

 tubercles, if they are perforated by a vascular bundle, as Eichwald 

 described (Traite de Paleontologie Vegetale, vol. ii., p. 53. 1870), 



Omitting the works of the systematists who have added nothing to 

 our knowledge of these plants, we come to a valuable paper by Feist- 

 mantel on the Coal-plants of Kralup (1871), in which he investigates 

 the nature of Halonia, and gives three plates of casts of specimens. 

 He points out the impo-rtance of the vascular scar in the centre of the 

 tubercle, and considers it to indicate probably an articulating surface. 

 But the great importance of his paper is the determination that the 

 leaf scars of Halonia regularis were the same as those of Lepidoden- 

 dron laricinum, Sternb., and he therefore concludes that these two 

 plants stand to each other in the closest relationship, if they be not 

 indeed one and the same plant (p. 30). 



The latest memoir on this subject is that by Mr. Binney, published 

 by the Palseontographical Society (1872). This is chiefly devoted to 

 the description of transverse sections of specimens exhibiting struc- 

 ture. The drawing and description of Mr. Dawes are confirmed by 

 the beautiful illustrations which accompany this paper. Notwith- 



1 Goldenberg overlooked Lindlcy and Hutton's earlier use of this name for a frag- 

 mentary fossil, which I have shown to be the part of a Calamite stem. See Woodward's 

 " British Fossil Crustacea of the Order Merostoraata," part iv., p. 168, Pal. Soc. 

 vol. ixvi. 1872. 



