160 PROCEEDINGS OE THE GEOLOGICAL SOCIErX. 



stated, it had previously been well known elsewhere. I regard these 

 plants, so weU described by Williamson, as true Calamites, in the 

 sense in which that word is used above. 



(2) The same palaeobotanist has independently expressed the be- 

 lief above stated, that the leaves of Calamites are distinct from those 

 of Aster ophyllites, and has also stated a distinction between those so- 

 called Volkmannice which may be regarded as fruits of Calamites 

 and those which belonged to Asteropliyllites *. He has also described 

 a specimen of Stigmaria showing the medullary rays, and otherwise 

 approaching to the structures which should be found in the roots of 

 the typical Sigillarim above described. 



(3) Schimper, in his ' Paleontologie Vegetale,' vol. xi., has treated 

 the Sigillarice very slightly. He adds no new facts of importance to 

 their history, does not separate them from the plants of the genus 

 Lepidophloios, usually mixed with them, refers the whole to one 

 genus, and places them with the Lycopodiaceae. 



(4) Binney, in the Palseontographical Society's Publications, 

 vol. xxiv., has described, under the name of Bowmanites cambrensis, 

 a very interesting plant, which I regard as a typical member of the 

 group AsteropJiyUitece, as distinguished from Calamitece. 



(5) Attention having been directed by Prof. Huxley to the pre- 

 sence of spore-cases in Coal, I have endeavoured to show, in a paper 

 in the ' American Journal of Science ' for April, that these bodies are 

 not a large constituent of ordinary Coal, and that any importance 

 which they possess in this respect is due to their identity in chemical 

 composition with those cortical and epidermal tissues which, like the 

 suberin of cork, are more nearly allied in composition to Coal than 

 any other recent vegetable matters, and better fitted, by their che- 

 mical and mechanical properties, for its production. 



EXPLANATION OF THE PLATES. 



Plate VIL 



Fig. 1. Sternhergia, pith of Dadoxylon; 1 a, section of one side, sliowing 

 diaphragms ; 1 h, section of a diapliragm and three wood-cells, 

 magnified ; 1 c, two wood-cells, higlily magnified, showing reticu- 

 lated walla. 



2. Sternhergia, pith of Sigillaria, natural size ; 2 «, 2 b, diseigerous 



tissue investing the same. 



3. Sternhergia, pith of Sigillaria, natural size ; 3 a, diseigerous and 



scalariform tissue. 



4. Sternhergia, natural size ; 4 a, reticulato-scalariform tissue. 



5. Sternhergia, natural size ; 5 «, 5 h, scalariform and reticulato-scalari- 



form tissue. 



6. Scalariform vessel of LejaidopJiloios. 



Plate VIIL 

 Fig. 7. Sternhergia, of Lepidodendroid tree ?, natural si^^ ; 7 a, SCalarifor'm 

 tissue. 

 8. Section of a flattened stem (Sigillaria?) 1 foot in diameter, converted 

 into coal, with Sternhergia-T^ith. 



■f Manchester Lit. and Phil. Soo. Proceedings, Feb. 1871. 



