338 CARDIOCARPALES [CH. 



seeds described by Geinitz as Cardiocarpon triangular e l , repre- 

 sented by well preserved impressions in the Dresden Museum, 

 appear to be of the Samaropsis type: the same author referred 

 some Samaropsis seeds to the Conifer Walchia, but Weiss 2 dissents 

 from this correlation as the seeds often occur in beds in which 

 Walchia is not represented. Renault states that the seeds of 

 the fertile shoot described by him as Cycadospadix Milleryensis* 

 from Autun [= Strobilites Milleryensis (Ren.)] closely resemble 

 Samaropsis fluitans Daws, as figured by Weiss. The suggestion 

 by White 4 that Samaropsis seeds were borne on fertile leaves of 

 Gangamopteris adds a further difficulty to the use of the generic 

 characters of Samaropsis as criteria of systematic position. The 

 Permian seeds figured by Goeppert 5 as Oreodoxites Martianus are 

 possibly specimens of Samaropsis. 



The designation Samaropsis, though usually restricted to 

 Palaeozoic species, is applied by some authors to 'winged' seeds 

 from Mesozoic strata ; but as some of the Jurassic seeds 6 so 

 named appear to have true wings like those of some recent 

 Conifers it is advisable to adhere to the more limited use of the 

 name. 



It is safe to assert that many Samaropsis seeds agreed generally 

 in structure with Cordaitean seeds such as the petrified examples 

 described by Brongniart as Cardiocarpus. The species Mitro- 

 spermum compressum 1 is an example of a petrified seed having 

 the external features of Samaropsis. 



Cardiocarpus. 



This generic title I propose to restrict to petrified seeds 

 exhibiting the characters described by Brongniart 8 and more 

 recently by Bertrand 9 in C. sclerotesta and C. drupaceus. In 

 general organisation seeds of this generic type agree with those 

 of recent Cycads and with the seed of Ginkgo biloba, but there 

 are certain distinguishing features. An important character is 



1 Geinitz (80) p. 22, PL in. figs. 1115. 



2 Weiss, C. E. (72) p. 208. 3 See page 141. 

 4 White (08) B. p. 563. See also Vol. H. p. 517. 



6 Goeppert (65) p. 146, PL xxvi. fig. 5. 



6 Heer (77) ii. PL xiv. ' See page 345. 



8 Brongniart (81) p. 20, PL n. 9 Bertrand, C. E. (08 2 ); (08 3 ). 



