LEPIDOPHLOIOS, AND ON THE BEITISH SPECIES OP THE GENUS. 555 



1836. Pachyphloeus, Gopp. (in part). Die fossilen Farrnkrduier, p. 468. 



1838. Zamites, Presl. in Sternb. (in part). Vers., ii. fasc. 7, 8, p. 195. 



1855. Cyclocladia, Goldenberg (not L. and H.). Flora Sarcep. foss., heft. i. p. 19. 



1867. Lomatophloios, Corda. Flora d. Vorwelt, p. 17. 



Generic Characters. — Arborescent lycopods, with dichotomous ramification'. Stems 

 and branches bearing much developed scale-like leaf-cushions, at or near whose summit 

 is placed the leaf-cicatrice. Leaf-cushions imbricated, pedicel-like, upright or deflexed, 

 exposed portion with straight sides or rhomboidal in outline, smooth or carinate ; some- 

 times provided with a small tubercle immediately beneath the leaf-cicatrice. Leaf- 

 cicatrices transversely oval, rhomboidal or rhomboidal-elongate, lateral angles rounded or 

 acute, upper and lower angles generally rounded, sometimes pointed ; within leaf- cicatrice 

 are three punctiform cicatricules, of which the central is largest and sometimes sub- 

 triangular in form. Fructification consisting of cones, stalked (?or sessile), borne on 

 specialised branches which show when decorticated, spirally arranged protuberances 

 (Halonia) ; in corticated condition the Halonial scars rise little above, or are on a level 

 with the bark, and are represented by a rosette of deflected leaf-cushions. Medulla of 

 delicate cells surrounded by a primary vascular axis composed of scalariform vessels which 

 diminish in size from within outwards, exogenous vascular zone only developed in speci- 

 mens advanced in age, bark consisting of three zones — the innermost of small cells, the 

 middle of larger and irregular dense cells, and the outer composed of narrow, dense, 

 prosenchymatous tissue ( — Lepidodendron fuliginosum, Williamson). 



In Britain — in the Upper Carboniferous — Lepidophloios is very rare in the Upper 

 Coal Measures, but common in the Middle and Lower Coal Measures ; of the two 

 divisions of the Lower Carboniferous, Lepidophloios is extremely rare in the Carboni- 

 ferous Limestone Series, but frequent in the Oil Shales and associated rocks of the 

 Calciferous Sandstone Series. 



The following species occur in Britain : — 



Lepidophloios laricinus, Sternberg. 

 Lepidophloios acerosus, L. and H., sp. 

 Lepidophloios, cf. macrolepidotus, Goldenberg. 

 Lepidophloios Scoticus, Kidston. 



Lepidophloios laricinus, Sternberg. 

 PI. I. fig. 4, 4a ; PL II. fig. 8, 8a, and 8b. 



1820. Lepidodendron laricinum, Sternb. Esse flore monde prim., vol. i. fasc. 1, pp. 23 and 25, pi. xi. 



figs. 2-4. 

 1854. Lepidodendron laricinum, Geinitz. Darst. d. Flora d. Hain.-Ebersd. u. d. Floehar-Kohlenbassins, 



p. 47, pi. xi. figs. 4-8. 

 1875. Lepidodendron laricinum, Feistmantel. Vers. d. bohm. Kohlendb., Abth. ii. p. 17, pi. iv. figs. 1-3 



(fig. 4 1) ; pi. v. figs. 1-4 (fig. 5 1) (not pi. xviii.) (including var. 



insigne, Peistm.). 



