354 CARDIOCAEPALES [CH. 



is 4-5 cm. long and 2-3 cm. broad, differing from S. indica 

 in its rather smaller size and in the slightly narrower nucule. 

 Though there is no decisive evidence as to the parent-plant the 

 occurrence of a specimen of this species partially covered by a 

 scale-leaf of a type 1 very similar to that which is generally recog- 

 nised as belonging to Glossopteris suggests the possibility that the 

 seeds may belong to that genus. Scale-leaves of Glossopteris 

 are described in Volume n., but it may be added here that leaves 

 similar in form to those from India, Australia, and elsewhere are 

 figured by Geinitz 2 from the Altai Mountains as Trigonocarpus ? 

 actaeonelloides : the specimens are represented with the basal 

 scar at the apex. 



Cordaicarpus. Geinitz. 



In view of the fact that the generic names Cardiocarpus, 

 Cordaicarpus, and other designations have been applied to casts 

 and impressions which cannot be distinguished by any constant 

 or important feature it is proposed to adopt the name Cordaicarpus 

 for platyspermic seeds, preserved as casts or impressions, having 

 a comparatively narrow border enclosing an ovate or cordate- 

 ovate nucule ; the base is either rounded or cordate. The choice 

 between Cordaicarpus and Samaropsis depends on the breadth of 

 the border. Cordaicarpus, though more suggestive of a Cordaitean 

 alliance, may in some cases be a Pteridosperm seed. 



Cordaicarpus Cordai (Geinitz). Lenticular seeds more or less 

 orbicular or broadly ovate (fig. 502, C, D), often slightly cordate 

 at the base of the nucule and with a broadly acute apex: the 

 border is narrow or sometimes hardly represented as in the seeds 

 described by Berger as Rhabdocarpus ovoides, a species similar to 

 but more oval than Cordaicarpus Cordai. The latter species 3 

 occurs in several coalfields in Britain, France, Germany, and 

 elsewhere. Fig. 502, C, shows a good example from the Middle 

 Coal Measures of Yorkshire, 9 mm. long by 8 mm. broad ; on the 

 very slightly cordate nucule are several faint ribs converging 

 towards the base and apex and between them fine striations, 



1 Vol. ii. p. 500. 2 Geinitz (71) p. 174, PL in. figs. 10, 11. 



3 Ibid. (55) A. PL xxi.; Zeiller (88) A. PL xciv. fig. 13; (06) B. p. 224; 

 Kidston (11) p. 240; Arber (14) p. 100. 



