172 STUDIES IN FOSSIL BOTANY 



A magnificent specimen of the latter kind was 

 discovered some years back by Mr. J. Lomax, and 

 described by Prof. F. E. Weiss. The stem, which has 

 a mean diameter of about 8 cm., bears, on opposite 

 sides, two series of large tubercles, with all the charac- 

 teristics of Halonia. The main stem, the structure of 

 which is perfectly preserved, agrees very closely with 

 that of Lepidophloios fuliginosus} Fig. 69 is from the 

 latter species, and shows a younger branch, also with 

 the Halonial mode of branching and apparently biseriate. 

 These specimens, together with others, in which the leaf- 

 bases are preserved, have been regarded as showing 

 that the Halonial shoots of Lepidophloios in some cases 

 bore their tubercles in two rows, though this conclusion 

 is disputed by Mr. Kidston, 2 who considers the attribu- 

 tion of these specimens to Lepidophloios as unproved. 



The tubercles of Halonia appear in most specimens 

 more prominent than they were in nature, owing to the 

 axis which bears them having lost its outer cortex. 

 In specimens with the natural surface preserved, the 

 tubercles appear rather as scars, but are quite distinct 

 from those of Ulodendron, owing to the absence in 

 Halonia of the cup-shaped area characteristic of the 

 former. The conclusion to which the facts appear to 

 point is that the so-called Halonia consisted of fertile 

 branches of Lepidophloios (and possibly other Lepido- 

 dendreae) bearing deciduous stalked cones. 



A specimen figured by Grand'Eury 3 appears to 



1 F. E. Weiss, "A Biseriate Halonial Branch of Lepidophloios fuligino- 

 sus," Trans. Linn. Soc. Bot. ser. ii. vol. vi. 1903. 



2 Kidston, " On the Internal Structure of Sigillaria elegans," Trans. Roy. 

 Soc. Edinburgh, vol. xli. Part iii. 1905. 



3 Grand'Eury, Bassin houiller du Gard, Plate vi. Fig. 17, 1890. 



