XXXVII] WILLIAMSONIA 443 



Williamsonia setosa Nathorst. 



The distinguishing features of this species 1 , founded on material 

 collected by Dr Halle from Lower Estuarine beds at Whitby, are 

 (i) the greater number of linear sporophylls which bear numerous 

 bristles or stout hairs, (ii) the loose coherence of the contracted 

 proximal portion of the linear segments, and (iii) a narrower 

 basal disc in place of the deeper cup of other species. One of the 

 specimens referred to this species, formerly regarded by Nathorst 

 as an infundibuliform organ of an ovulate strobilus of W. gigas 2 , 

 bears a striking resemblance to an Indian fossil described by 

 Feistmantel from India 3 . 



INDIAN SPECIES OF WILLIAMSONIA (FLOWERS). 



Several specimens of Williamsonia have been described from 

 the Rajmahal and other Jurassic series in India, some of which 

 exhibit a close agreement with Williamsonia gigas. It is, however, 

 noteworthy that no fronds of the Zamites gigas type have been 

 discovered in Indian beds; on the other hand the association of 

 fronds of the same type as Ptilophyllum pecten with Williamson ian 

 strobili is significant, as also the occurrence of stems apparently 

 identical in surface-features with English and Mexican species. 



Williamsonia sp. 



Oldham and Morris 4 figured a specimen from the Rajmahal 

 Hills consisting of a circular disc enclosed by a zone of 'closely 

 packed tubes,' the basal portion of an ovulate Williamsonia 

 strobilus, which they regarded as a pressed mass of young leaves 

 'probably related to Palaeozamia' [Ptilophyllum]. The figured 

 specimen shows that the radially disposed 'tubes' surrounding 

 the circular area are interseminal scales some of which are seen 

 at the periphery in surface-view as small polygonal areas as in 

 English specimens. Feistmantel 5 refigured this specimen and 

 referred it to Williamsonia gigas though on insufficient grounds. 

 To the same species Feistmantel 6 assigns two other specimens 

 from the Rajmahal series, one of which consists of several narrow 



1 Nathorst (11) p. 17, PI. iv. 2 Nathorst (09) PI. vn. fig. 1. 



3 See page 444. 



4 Oldham and Morris (63) B. PL xxxn. fig. 2. 



5 Feistmantel (77 2 ) p. 76; (77 5 ) PL n. fig. 5. Ibid. (II 2 ) PL XLIV. fig. 2. 



