XXVIl] NEUROPTERIS 565 



Archaeopteris was regarded by Carruthers as a fern closely 

 allied to recent species of Hymenophyllaceae, but this conclu- 

 sion was based upon an interpretation of the fertile segments 

 which Kidston^ has shown to be incorrect. The latter author 

 regarded the presence of stipules and the structure of the 

 exannulate sporangia as evidence of a Marattiaceous alliance. 

 In a later reference to Archaeopteris, Kidston expresses the 

 opinion that the genus is not a true fern but a member of the 

 Cycadofilices or Pteridosperms, a view shared by Grand'Eury= 

 and doubtless by many other palaeobotanists. The sporangia 

 of Archaeopteris appear to be of the same type as those of 

 Dactyloiheca (fig. 290, E, p. 399). Schmalhausen gave expression 

 to his disagreement with Nathorst and other authors who 

 referred Archaeopteris to the Marattiaceae by proposing the 

 distinctive group-name Archaeopterideae. 



There can be little doubt that the reproductive organs of 

 Archaeopteris so far discovered are microsporangia, and that the 

 plant bore seeds. The sporangia are larger than those of any 

 known fern and, as Kidston points out, they are similar to those 

 of Crossotheca which he has shown to be microsporangia of the 

 Pteridosperm Lyginodendron. The presence of stipules in 

 Archaeopteris hibernica, A. fimhriata, A. archetypus (fig. 369, 

 D) and probably throughout the genus does not materially 

 affect the question of taxonomic position. Stipules are a 

 characteristic feature of Marattiaceae and, in a reduced form, 

 of Osmundaceae, but similar appendages are borne at the base 

 of the petiole of the Cycad Ceratozamia. The occurrence of 

 Aphlebiae on the rachis of Archaeopteris is a feature shared by 

 the fronds of Neuropteris and other Pteridosperms. 



Neuropteris. 



The fronds for which Brongniart' created this genus, 

 though suspected by Stur in 1883 as wrongly classed among 

 the ferns, have only recently been shown to be the leaves of 

 Pteridosperms. As yet only one case is recorded in which 



> Kidstou (882). 2 Grand'Eury (08). ' Brongniart (22) A. 



