XXXVin] CAEPOLITHUS 497 



ferales. While the seeds of the Bennettitalesare clearly distin- 

 guished by their much smaller size from those of modern Cycads, 

 many of the latter agree in size and form with those of some other 

 Gymnosperms and in the absence of anatomical details could not 

 easily be identified as fossils. Some of the examples included in 

 the miscellaneous collection described by authors as species of 

 Carpolithus or Carpolithes agree .closely in external features with 

 the seeds of modern Cycads, but it is seldom possible to accept 

 them as undoubted records of Cycadalean plants. 



The general conclusion is that such meagre evidence as we 

 possess afiords strong confirmation of the conclusion based on 

 stems and foliage from Jurassic and Cretaceous strata^ namely 

 that the present representatives of the Cycadophyta are a rela- 

 tively late product of evolution, though retaining in their ana- 

 tomical features many survivals from a remote antiquity. The 

 occurrence of Cycadean characteristics in the vegetative organs 

 of the MeduUoseae and the recurrence of what may be called 

 the Cycadean seed-plan, with certain more or less striking pecu- 

 liarities reminiscent of earlier stages of evolution, in several types 

 of Palaeozoic seeds such as Cycadinocarpus, Stephanos fermum, 

 Lagenostoma and others bear testimony to the antiquity of the 

 Cycadean stock. 



CARPOLITHUSi. Linnaeus. 



This generic name, as Nathorst^ has recently pointed out, was 

 used by Linnaeus in 1768 for 'Phytolithus fructus' and has 

 therefore priority over Sternberg's genus Ca/rpolites employed in 

 1825. Lester Ward^ attributes CarpoUthus to Stokes and Webb 

 (1824) and states that in the plural form the name was used by 

 Walch in 1771. CarpoUthus is a convenient term to apply to 

 fossil seeds that cannot be assigned to a particular group of 

 plants and which do not exhibit any peculiarities of form suffi- 

 ciently striking to deserve generic recognition. Pomel* proposed 

 the genus Ulospermum but it never came into general use. 

 Schimper's genus Cycadinocarpus and Saporta's Cycadeospermum 



' For further reference to this generic name, as applied to Palaeozoic seeds, 

 see page 364. 



2 Nathorst (14) p. 33. ' Ward (00) B. p. 363. 



« Pomel (49) p. 16. 

 s. in 32 



