CARBONIFEROUS LYCOPODS AND SPHENOPHYLLS. 127 



cone, though the leaf whorls are superposed. 1 According to the 

 investigations of Williamson and Scott, the sporangiophores are 

 most probably modified segments of the bract, and not indepen- 

 dent outgrowths of the axis. They possess a small vascular 

 bundle. 2 



The axis of the cone contains a solid hexarch vascular cylinder, 

 bluntly triangular, with concave sides. 3 The peripheral scalari- 

 form tracheides are smaller than the central tracheides, with 

 pitted walls. 



Sphenophyllum emarginatum, Brongniart. 



1822. Sphenophyllites emarginatus, Brongt. Class d. veget.foss., 



pp. 34 and 89, PL II., figs. 8a and 8b. 

 1828. Sphenophyllum emarginatum, Brongt. Prodrome, p. 68. 



The structure of the cone of this species appears to be similar 

 to that of Sphenophyllum cuneifolium. The specimen described 

 by Zeiller was somewhat imperfectly preserved, but the sporangia 

 seem to be arranged in three or several concentric circles, and 

 from their position seem also to have been attached to 

 sporangiophores. 4 ' 5 



Sphenophyllum Romeri, Solms-Laubach sp. 



1895. Bowmanites Romeri, Solms-Laubach. Jahrb. d. k. k. geol. 

 Reichsanstalt, Vol. XLY., Heft. 2, p. 225, Pis. IX.-X. 



1 Williamson and Scott, Phil. Trans., 1894, p. 934. 



2 Williamson and Scott, Mem. I., Phil. Trans., Vol. CLXXXV., pp. 937 

 and 943. 1895. 



3 Scott, Phil. Trans., Vol. CLXXXIX. (B.), p. 25, 1897. 



4 Zeiller, Constitution d. appareilfruct. d. Sphenophyllum, p. 24, PL II., 

 fig. 4. 



5 M. Zeiller reviews other species of Sphenophyllum of which more or 

 less perfect cones have been discovered, but none of these afford very clear 

 evidence as to the number or mode of attachment of the sporangia. The 

 specimens mentioned are : — Sphenophyllum gracile, Crepin; Sohenovhyllum 

 oblong if olium, Germar and Kaulfuss; Sphenophyllum verticillatum, Schl. 

 sp. ( — Sphenojyhylhim Schlotheimii, Brongt.); SpheiiQphyllum angusti- 

 f olium, Germar ; Sphenophyllum tenerrimum, Ett. ; Sphenophyllum Sachsei, 

 Stur. ; and Sphenophyllum ccstatum, Stur. The last-mentioned species, 

 and also most probably Sphenophyllum Sachsei, should be referred to 

 Sphenophyllum cuneifolium, Sternb. sp. 



