360 MISCELLANEOUS SEEDS [CH. 



the Kidston collection from the Lower Calciferous sandstone of 

 Midlothian. Nothing definite can be said as to the parent-plant, 

 but it is significant that in Midlothian Rhynchogonium sulcatum 

 occurs in a bed full of isolated pinnules of a Cardiopteris almost 

 to the exclusion of any other fossils 1 . 



The seed figured by Nathorst 2 from the Culm of Spitzbergen 

 as Lagenospermum ? glandiforme agrees closely with Rhynchogonium 

 and Boroviczia, and it is impossible to decide whether the lobed 

 appearance is due to the presence of a cupule or to the divisions 

 of an integument. 



Boroviczia. Zalessky. 



The specimens from Lower Carboniferous beds in Russia 3 

 on which this genus was founded are perhaps unnecessarily 

 separated from Rhynchogonium', they are ovate and beaked, 

 10 mm. long with a maximum breadth of 6 mm. The type- 

 species, Boroviczia Karpinskii (fig. 506, I), is represented both by 

 specimens in which the cast is complete and by others in which 

 the apical snout of the integument is split into separate lobes 

 identical in form and apparently in number with those of Rhyncho- 

 gonium. Nathorst 4 , who retains the generic name and describes 

 two additional species from Spitzbergen, points out that in 

 Boroviczia the tapered apex is more sharply differentiated from 

 the broader basal portion, a difference hardly worthy of generic 

 recognition. If Boroviczia is retained as a genus distinct from 

 Rhynchogonium it should include the seeds described by Young 

 as Trigonocarpum gloagianum. 



Diplopterotesta. Nathorst. 



Diplopterotesta spitzbergensis (Heer). Heer 5 included in Sama- 

 ropsis some seeds, described as Samaropsis spitzbergensis, from 

 Lower Carboniferous strata in Spitzbergen which differ consider- 

 ably from typical examples of the genus. These have recently 

 been made the type of a new genus Diplopterotesta 6 : they are 

 platyspermic seeds nearly twice as long as broad, 6 9x 3*5 5mm., 



1 For this information I am indebted to Dr Kidston. 



2 Nathorst (14) p. 32, PL xv. fig. 58. 



3 Zalessky (05). 4 Nathorst (14) p. 27, PI. v. figs. 1922; PL xv. fig. 



5 Heer (77) i. p. 24, PL v. figs. 1822. 



6 Nathorst (14) p. 35, PL xv. figs. 7782. 



