266 



COBDAITEAE 



[CH. 



between seeds and vegetative organs, and while it is possible to 

 state with confidence that many of the seeds represented by 

 impressions described as species of Samaropsis and Cordaicarpus 

 are undoubtedly Cordaitean, it is certain that not all seeds refer- 

 able to these genera were borne by Cordaitalean plants. Cordaitean 

 seeds are characterised by certain morphological features recalling 

 those found in recent Cycads and in the seeds of Ginkgo as 

 illustrated by species of Cardiocarpus and some allied types. 

 As most of the Palaeozoic seeds known in a petrified state cannot 

 be assigned to their parent-plants they are dealt with in a separate 

 chapter 1 . 



Cordaianthus Pitcairniae (Lindley and Button). 



This type of inflorescence 2 is considered by Kidston to belong 

 to the tree which bore leaves known as Cordaites principalis, but 

 if this is the case it is probable that the stem possessed the 

 anatomical characters of Mesoxylon. 



FIG. 480. A, Cordaianthus Pitcairniae with Samaropsis seeds. B, Cordaianthus 

 Volkmanni. B', portion of B enlarged. (A, B, nat. size; Kidston Coll. 2374, 1174.) 



The portion of an inflorescence shown in fig. 480, A, from the 

 Middle Coal Measures of Yorkshire, illustrates the occurrence of 



1 See Chap. xxxv. 



2 Lindley and Button (33) A. PL LXXXH.; Carruthers (72 3 ) B. p. 7; Kidston 

 (03) B. p. 782; (11) p. 235. 



