xxxv] 



RHYNCHOGONIUM 



359 



flora of Spitzbergen Nathorst 1 discusses the morphological nature 

 of Rhynchogonium seeds and describes additional specimens. 

 Without the aid of petrified examples it is hardly possible to 

 determine the true nature of the fossils. 



FIG. 506. A, Holcospermum sulcatum. B, C, Codonospermum anomalum. 

 D, Diplopterotesta spitzbergensis (x 3). E, Gnetopsis elliptica (cupule). 

 F, Thysanotesta sagittula. G, Rhynchogonium costatum. H, Hexagonocarpus 

 Noeggerathi. I, Boroviczia Karpinskii. K, Rhabdospermum tunicatum. 

 (A, Kidston Collection; B, after Grand' Eury ; C, after Renault and Zeiller; 

 D, F, G, after Nathorst; E, after Renault; H, after Williamson; I, after 

 Zalessky; K, after Berger.) 



Some specimens of Rhynchogonium sulcatum in Dr Kidston's 

 collection show the original surface-features: the carbonised 

 integument is divided in the upper region into linear lobes separated 

 from one another at their origin by fairly wide sinuses, \ type of 

 integument suggesting comparison with Physostoma. This species 

 was originally described by Lindley and Hutton as Carpolithes 

 sulcata 2 from Lower Carboniferous rocks at Newhaven in Scotland 

 and has recently been figured by Zalessky 3 from specimens in 



1 Nathorst (14) p. 23, PL xv. figs. 4451. 



2 Lindley and Hutton (37) A. PL 220. 



Zalessky (05). 



