Royal Society, London. 239 



C heirostrobus , gen. nov. 



Cone consisting of a cylindrical axis, bearing numerous 

 Compound sporophylls, arranged in crowded many-membered 

 verticils. 



Sporophylls of successive verticils superposed. 



Each sporophyll divided, nearly to its base, into an inferior 

 and a superior lobe ; lobes palmately subdivided into long segnients, 

 of which some (probably the inferior) are sterile, and others 

 (probably the superior) fertile, each segment consisting of an 

 elongated stalk bearing a terminal lamina. 



Laminae of sterile segments foliaceous ; those of fertile segments 

 (or sporangiophores) peltate. 



Sporangia large, attached at the end remote from the axis, to 

 the peltate laminae of the sporangiophores. 



Sporangia on each sporangiophore, usually four. 



Spores very numerous in each sporangium. 



Wood of axis polyarch. 



C. Pettycurensis, sp. nov. 



Cone, o — 4 cm in diameter, seated on a distinct peduncle. 

 Sporophylls, twelve in each verticil. 



Each sporophyll usually sexpartite, three segments belonging 

 to the inferior, and three to the superior, lobe. 



Sporangia densely crowded. 



Spores about 0,065 mm in diameter. 



Horizon : Calciferous sandstone. 



Locality: Pettycur, near Burntisland, Scotland. Found by 

 Mr. James Ben nie, of Edinburgh. 



Both generic and specific characters are manifestly subject to 

 alteration, if other similar fossils should be discovered. In the 

 meantime the above diagnoses are given, in order to facilitate 

 identification. 



A ffinities. 



Any füll discussion of affinities must be reserved for the 

 detailed memoir, which 1 hope to lay before the Royal Society in 

 a short time. At present only a few suggestions will be offered. 



The idea of a near relationship to Lepidostrobus — so specious 

 at first sight — is negatived by accurate investigation. There may 

 have been a certain resemblance in external habit, as there is in 

 the naked-eye appearance of the sections, but this means nothing 

 more than that the specimen is a large cone, with crowded 

 sporophylls and radially elongated sporangia. The only real 

 resemblance to Lepidostrobus is in the polyarch Strand of primary 

 wood, but even here the details, as, for example, the structure of 

 the tracheae, do not agree. In other respects the differences from 

 any Lepidodendroid fructification are as great as they can be. 



I do not doubt the genus with which Cheirostrobus hos most 

 in common is Sphenophyllum. The chief points of agreement are 

 as follows. 



