CYCADOFILICALES 



31 



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y^f« 



Fig. 25. — Lagenostoma Lomaxii 

 (restored): the seed is surrcmnded 

 by a glandular cupulc. — After 

 Oliver and Scott (48). 



THE MEGASPORANGIUM 



Numerous detached paleozoic seeds have been discovered, hut 



it must be remembered that they inckidc the seeds of both Corchiitales 



and Cycadofilicales. The seeds defi- 

 nitely connected with Cycadofilicales 



are comparatively very few, but the 



structure of at least two of them is 



known with remarkable completeness. 

 Lagenostoma. — In 1903 Oliver 



and Scott (39) announced that a 



species of this seed genus is the seed 



of Lyginodendron Oldhamium, and in 



the following year the full account 



appeared (48). The seed species was 



a new one, and was described as Lage- 



nhitoma Lomaxii (fig. 25). The seeds 



were not found in actual organic con- 

 nection with the foliage (Sphenopleris) 

 of Lyginodendron, but the numerous and 

 peculiar capitate glands borne on the 

 cupule correspond in every detail to those 

 on the vegetative organs of the associated 

 Lyginodendron, and represent a character 

 not possessed by any other associated 

 j^lant. There seemed to be no doubt 

 that the reference of the seed to Lygino- 

 dendron was fully justified, a conclusion 

 further confirmed by a comparison of 

 the anatomical details. Another species 

 of Lagenostoma {L. ovoides) was known; 

 and later Arber (51) described L. Kids- 

 tonii and L. Sindairii from casts, but 

 important in that the seeds were con- 

 nected with branching axes that represent 

 naked branches of a frond (fig. 26). It is 



evident, therefore, that the leaves of Lyginodendron were dimorphic, 



one form being the familiar sterile foliage of the Sphenopleris type, 



Fig. 26. — Lagenostoma Sin- 

 dairii: two seeds on y)ranches 

 of the rachis, each seed sur- 

 rounded by a cupule. — After 

 Arber (51). 



