TRANSACTIONS OF SECTION K. 945 



3i On the Presence of Seed-like Organs in certain Palceozoic Lycopods. 



£yD.B.. Scott, F.B.S. 



Specimens discovered by Messrs. Wild and Lomax ia the Gauister beds of the 

 Lower Coal-measures of Lancashire prove that the seed-like bodies described by 

 Williamson under the name of Cardiocarpon ano^nalum were borne on strobili, 

 agreeing completely in morphology and anatomy with Lepidostrohus. 



Each megasporangium, which, as usual in Lepidodendreae, was seated on the 

 upper surface of the sporophyll, became enclosed, when mature, in an integument 

 springing from the tissue of the sporophyll-pedicel. The integument closedln over 

 the top of the sporangium, leaving only a narrow crevice or micropyle, which 

 differed in its elongated, slit-like form from the more or less tubular micropyle of 

 an ordinary seed. 



Within the megasporangium four megaspores were produced, one of which 

 occupied almost the whole of the sporangial cavity, while the other three remained 

 small, and were evidently abortive. 



The integumented megasporangium, containing the single function almegaspore 

 or embryo-sac, became detached, together witli the remains of its sporophyll, from 

 the cone. It appears to have been indehiscent, and presents close analogies with a 

 true seed. 



In a specimen from Burntisland, practically identical with the Coal-measure 

 form, tliough presumably of a different species, the prothallus was found fairly 

 preserved. It formed a large-celled tissue, occupying the interior of the functional 

 megaspore. 



In a male strobilus. probably of the same species as the Coal-measure specimens 

 above described, the microsporangia were found to be provided with integuments, 

 resembling those of the megasporangia but more widely open. 



It is proposed to give the generic name Lepidocarpon to the Lepidostroboid 

 fructification now described.' Though its seed-like reproductive bodies were 

 referred to Cardiocarpon by Williamson, they have no affinity with the Cordaitean 

 seeds constituting the genus Cardiocarpon of Brongniart, to which the true 

 C. a7iomalum of Carruthers belongs. 



4. The Primary Structure of certain Palceozoic Stems referred to 

 Araucarioxylon. By D. H. Scott, F.E.S. 



The chief object of the present communication is to exhibit some illustrations 

 of facts already briefly recorded elsewhere.^ 



The genus Araiccarioxi/lon is an artificial one, founded to include fossil speci- 

 mens with secondary wood resembling that of a recent Araucaria. The Paleo- 

 zoic forms of Araiccavio.vylon have been shown to belong in most cases to the 

 stems of the extinct Gymnospermous order Cordaiteae, which was in some respects 

 intermediate between Cycadales and Coniferae. 



The Cordaitean stems hitherto investigated appear to have resembled ConiferjB 

 in the development of their wood, for the spiral first-formed tracheides are found 

 in contact with the pith, the whole of the wood, primary as well as secondary, 

 having thus been developed in centrifugal order. 



The specimens now illustrated are peculiar in possessing distinct strands of 

 primary wood in the pith. They belong to two species, bothfr .m the Lower Car- 

 boniferous rocks of Scotland and the North of England. 



In one, Araucario.vi/lon fasciculare, sp. nov., the pith is small, but the primary 

 strands of xylem are of large size, attaining their maximum diameter when about 

 to pass out towards a leaf. Their structure is mesarch, and they closely 



' A somewhat fuller account of Lppidocarpon has been communicated to the 

 Royal Society, and a complete illustrated description is in preparation. 



* Scott, ' On the Primary Wood of certain Araucarioxylons,' Annals of Bolanv. 

 December 1899. 



1900. 3 p 



