362 MISCELLANEOUS SEEDS [CH. 



under several generic names and not uncommon in Upper Palaeo- 

 zoic rocks in Europe and North. America, which in most cases 

 cannot be assigned to a genus implying the possession of certain 

 anatomical characters. This type was figured by Sternberg 1 from 

 the Coal Measures of Radnitz as Carpolites sulcatus. Some 

 'fruits' collected on the beach near Newhaven, Midlothian, 

 from the Calciferous Sandstone series, are figured by Lindley 

 and Hutton 2 as Carpolithes sulcata, but as already stated these 

 have been transferred 3 to the genus Rhynchogonium. Several 

 authors have referred specimens of the type now included in 

 Holcospermum to Rhabdocarpus, but that genus, as stated on a 

 previous page, is restricted to seeds agreeing in form with R. 

 tunicatus. Renault 4 instituted the genus Colpospermum for a 

 partially petrified seed from Commentry agreeing externally with 

 Carpolites sulcatus Sternb. and regarded by him as specifically 

 identical, characterised by longitudinal ribs which represent folds 

 of the testa, the intervening grooves being occupied by an irregular 

 reticulum formed by occasionally anastomosing smaller ribs. 

 The generic name Colpospermum should therefore be reserved 

 for ribbed seeds showing the anatomical features described by 

 Renault and Zeiller: its application to Sternberg's species is 

 inadvisable on the ground that we have no information with 

 regard to the morphological nature of the ribbing. More recently 

 Arber 5 has proposed the name Platyspermum, a name previously 

 applied to a Cruciferous plant, for Stephanian and Permian seeds 

 formerly assigned to Berger's genus Rhabdocarpus, which are 

 symmetrical in two planes. In this genus he includes Platysper- 

 mum sulcatum and among other species P. Kidstoni founded 

 on a seed originally identified by Kidston 6 as Rhabdocarpus 

 multistriatus Sternb. which, though probably' a distinct species, 

 is of the same general type as C. sulcatus Sternb. 



The cast represented in fig. 506, A, from the Middle Coal 

 Measures of Yorkshire is 3-5 cm. long and has 18 regular longi- 



1 Sternberg (38) A. PL x. fig. 3. 



2 Lindley and Hutton (37) A. PL 220. 3 Zalessky (05) p. 119. 



4 Renault and Zeiller (88) A. p. 652, PL LXXII. figs. 6366; Renault (96) A. 

 p. 400; (93) A. PL LXXXIV. fig. 3. 



5 Arber (14) p. 95, PL vi. fig. 11. 



6 Kidston (88) B. PL xxm. fig. 4. 



