STIGMARIA. 293 



support to this assumption, as has been justly urged by Williamson and 

 Hartog l . It is true that they themselves go too far again in the following 

 sentence 2 : ' two or four shoots of Stigmaria of equal size, opposite or verti- 

 cillate, are found at the base of the stem of Sigillaria, which makes it impos- 

 sible to admit that Sigillaria was at first an ascending bud,' &c. In any 

 case we shall do well to withhold assent to these views of the French authors, 

 so long as they are unable to produce stronger proof in support of them. 



Other remains resembling Stigmaria from the Devonian formation 

 have been described under the names Cyclostigma 3 and Arthrostigma 4 , but 

 they are only known in impressions, and are therefore of small importance 

 to the botanist. Cyclostigma kiltorkense, Haught. with some other forms 

 is abundant in the yellow Upper Devonian sandstone of Kiltorkan Hill in 

 Ireland, and occurs also according to Heer 5 in the deposits of his Ursa 

 stage (the confines of the Devonian and Carboniferous formations) in Bear 

 Island. According to Haughton the smooth or wrinkled surface of the 

 fossil is marked with small circular distant scars in regular many-membered 

 whorls. Heer, who had specimens from Bear Island before him, declares 

 that Haughton's drawings are bad, and figures a quincuncial position of 

 the scars exactly like that of Stigmariae ; and this is found in an Irish 

 specimen which I saw in the Museum at Breslau, and which is figured by 

 F. Romer 6 . Other similar remains have been repeatedly described ; for 

 example, by Schmalhausen 7 from the Ursa stage of Siberia, by Weiss 8 

 (Cyclostigma hercynicum), by O. Feistmantel 9 (C. australe, O. Feistm.) 

 from the confines of the Devonian and Carboniferous formations in New 

 South Wales and Queensland. 



Dawson has devoted an entire plate to his genus Arthrostigma dis- 

 covered in the Lower Devonian beds of Gasp6 in Canada ; its branched 

 axes are striated and furrowed and beset with very irregular whorls of 

 round scars, to which sharp-pointed thorn-like appendages with a broad 

 base are attached at right angles to the axis. 



1 Williamson and Hartog (5), p. 349. 2 Williamson and Hartog (5), p. 349. 



3 Haughton (1) ; Schimper (1), vol. iii, p. 530. * Dawson (1), vol. i, p. 41 ; t. 13; Schimper 



(1), vol. iii, p. 549. 5 Heer (5), vol. ii, I, p. 43 ; t. n. 6 F. Romer (1), vol. i, p. 225. 



7 Schmalhausen (3), t. i. 8 Weiss (3), p. 175, t. 7. 9 O. Feistmantel (1), in, Part II, 



PP- 7. 75 ; t. i, f. 6, and t. 5, f. i. 



