XVIIl] BOTHRODENDRON 251 



were not generically distinct from the fossils originally figured 

 by Rhode as Ulodendron. It was Prof Zeiller who first 

 demonstrated that the English authors were justified in their 

 choice of a new designation for stems with large depressions 

 in association with minute leaf-scars. In 1859 Haughton' 

 proposed a new family name Cyclostigmaceae for some Upper 

 Devonian plants from County Kilkenny, Ireland : he described 

 three species of his new genus Gyclostigma, Cyclostigma 

 kiltorkense G. minutum, and C. Griffithsi; these are now generally 

 recognised as a single species of Bothrodendron, though, as 

 Nathorst suggests, the Irish plant should perhaps be separated 

 as a sub-genus Bothrodendron (Gyclostigma) by reason of certain 

 minor difierences which distinguish it from other species of 

 the genus. 



Another generic name, Rhytidodendron, was instituted by 

 Boulay in 1876 for stems characterised by a finely wrinkled 

 bark and small spirally disposed leaf-scars. A short description 

 of this type, which occurs in the Middle and Lower Coal- 

 Measures, may serve to illustrate the external features of 

 the commonest British example of the genus. 



a. Bothrodendron minutifolium (Boulay.) Figs. 212, A, C, D ; 

 213. 



1875. Lycopodium earbonaceum {Lycopodites carbonaceus), Feist- 

 mantel, Palaeontographica xxxiii., PI. xxx. figs. 1, 2 ; p. 183. 



1876. Rhytidodendron minutifolium, Boulay, Terr. Houill. Nord 

 France, p. 3ft, PI. in. fig. 1. 



1886. Bothrodendron minutifolium, Zeiller, Bull. Soc. Geol. France 

 [iii] XIV. p. 176, PI. IX. figs. 1, 2. 



1888. LepidoUrobus Olryi, Zeiller, Flor. Valenciennes, p. 502, PI. 

 LXXVII. fig. 1. 



1889. Bothrod&ndron minutifolium, Kidston, Trans. R. Soc. Edin- 

 burgh, Vol. XXXV. Pt ii. 



1893. SigUlaria {Bothrodendron) minutifolia, Weiss and Sterzel, 

 K. Preuss. Geol. Landesanstalt, Heft 2, p. 49, PI. i. figs. 3 and 4 ; 

 PL II. figs. 8 and 9. 



1904. Bothrodendron minutifolium, Zalessky, Mem. Com. Geol. Russie, 

 PI. VI. fig. 6. 



In habit a plant of Bothrodendron recalls Lepidodendron 



and recent species of Lycopodium; the slender dichotomously 



1 Haughton (59). 



