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On the Palaeozoic Seed, Lagenostoma Lomaxi. [Dec. 15, 



" On the Structure of the Palaeozoic Seed, Lagenostoma Lomaxi, 

 with a Statement of the Evidence upon which it is referred 

 to Lyginodendron!* By Professor F. W. Oliver and 

 Dr. D. H. Scott, F.E.S. Eeceived December 15, 1903 — 

 Read January 21, 1904. 



(Abstract.) 



The present communication deals with the structure of Lagenostoma 

 Lomaxi, a fossil seed from the lower coal-measures, and with the 

 evidence upon which the authors refer it to the well-known 

 carboniferous plant, Lyginodendron. 



It is found that this species of Lagenostoma, especially in its young 

 form, was inclosed in a husk or cupule, borne on a short pedicel. 



The seed, which is of Cycadean character, is fully described, and its 

 relation to other fossil and recent seeds discussed. 



The cupule inclosing the seed was borne terminally on a pedicel ; it 

 formed a continuous, ribbed cup below, and divided above into a 

 number of lobes or segments. Externally, both pedicel and cupule 

 were studded with numerous prominent multicellular glands of 

 capitate form. The anatomy indicates that the whole organ was of a 

 foliar nature, 



A comparison with the vegetative organs of Lyginodendron 

 Oldhamium, with which the seeds are intimately associated, demon- 

 strates a complete agreement in the structure of the glands and in the 

 anatomy of the vascular system. Where vegetative and reproductive 

 organs, presenting identical structural features, not known to occur in 

 other plants, are thus found in close and constant association, the 

 inference that the one belonged to the other appears irresistible. 



As regards the position of the seed on the plant, two possibilities 

 are discussed : the cupule, with its pedicel, may either represent an 

 entire sporophyll, or a modified pinnule of a compound leaf. Either 

 view is tenable, but various comparative considerations lend a some- 

 what greater probability to the second alternative. 



In the concluding section of the paper, the systematic position 

 of Lyginodendron is discussed. On the whole of the evidence, the 

 position of the genus as a member of a group of plants transitional 

 between Eilicales and Gymnosperms appears to be definitely estab- 

 lished. While many Filicinean characters are retained, the plant, 

 in the organisation of its seed, had fully attained the level of a 

 Palaeozoic Gymnosperm. There are many indications that other 

 genera, now grouped under Cycadofilices, had likewise become seed- 

 bearing plants. It is proposed to found a distinct class, under the name 

 Pteridospermce, to embrace those Palaeozoic plants with the habit and 



