HALONIA. 89 



"Dans le gres houiller de Hallivvell et Peel, pres de Bolton (Angleterre), pres de 

 Duttweiler, pays de Saarbrucken." 



Dr. Schiraper, in a supplementary note of the same work, at p. 117, states that, after 

 his general considerations on Stigmaria had been printed off, he heard of the discovery 

 (in the quarries of the grauwacke, near Thun) of a trunk furnished with roots. This 

 trunk has been obtained by Doctor Faudel for the Museum of Colmar; and when he (Dr. 

 Schimper) examined the specimen, it completely confirmed his opinion previously expressed 

 that Stigmaria might have belonged to other trees besides Sigillaria. He found, in fact, 

 that the trunk in question furnished with a Stigmarioid root was indeed a trunk of 

 Knorria longifolia, whose base agreed with Ancisfrojjhgllum, while its middle portion cor- 

 responded with Didymaphyttum Schottini, Gcepp. 



VI. Description of the Specimens. 

 § 1. Specimen No. 34, Halonia regularis. PL XV, figs. 1 — 4. 



Por this instructive specimen (PI. XV, fig. 1, magnified three and one fifth diameters) 

 I am also indebted to Mr. Dawes, who discovered it in the clay-ironstone of the Coal- 

 measures near Dudley. The original fossil from which the slices were made is not now 

 to be found, so I cannot describe, from my own knowledge, what were its external 

 characters ; but, from Mr. Dawes' description, it no doubt belonged to the genus 

 Halonia ; and, from its identity in structure with other specimens of my own, intended 

 to be hereinafter described, it most probably belonged to the species regularis. 



The transverse section of the specimen, as shown in fig. 1, is irregularly oval, flattened 

 on one side, and measures one and five eighths inches across its major, and one and three 

 eighths inches across its minor axis. The central axis is near the middle of the specimen. 

 The medulla in this section appears to be much disarranged and destroyed, so that we 

 cannot tell whether it consisted of orthosenchymatous tissue, like that in Lepidodendron, 

 or not. The woody cylinder, enclosing the medulla, is also considerably disarranged ; 

 but there is sufficient evidence to show that it was composed of barred tubes or utricles. 

 The mouths of some of these appear to be filled with a very fine orthosenchymatous tissue, 

 of a bright wine colour, probably a portion of the medulla squeezed into them during the 

 process of mineralization. The outside of the woody cylinder is bordered by an irregular 

 band, dark in colour, as drawn in the plate ; but, when viewed by transmitted light, it is 

 seen to be of a bright wine colour. Prom near this zone proceed the large vascular 

 bundles, which go outwards through the parenchyma to the leaves or roots (whichever 

 of those appendages they may prove to be). The portion of the stem from the woody 

 cylinder to the irregular light-coloured line near the outside of the specimen consists of 



