CYCADOFILICALES 23 



H. Grievii as "a fernlike plant, with a long, upright or perhaps 

 trailing, ribbed stem, bearing large and graceful, finely divided fronds, 

 much resembling those of some recent Asplenium." The foliage of 

 Lyginodendron Oldhamium is Sphenopteris Honinghausii, the leaves 

 being very large and pinnately dissected. The leaflets are described 

 (86) as fleshy and incurved, with often dilated vascular endings as 

 though connected with glands, and suggesting plants of the salt water 

 swamps of today. Scott (24) thinks that it was probably "a climbing 

 plant of the scrambler type, a suggestion which is confirmed by the 

 presence of spines on the stem, and on all parts of the compound 

 leaves."' To this Sphenopteris type of foliage have been referred 

 numerous sporangia, both those supposed to be of ferns and those of 

 Cycadofilicales. It has been suggested (82) that the species with 

 forked rachis are probably Cycadofilicales, and that some of the 

 others are probably ferns. 



No leaves have been definitely associated with the stem genus 

 Cycadoxylon, but the associated occurrence of distinctly cycadean 

 leaves, resembling those of Dioon and of Zamia, suggests the pos- 

 sibility that the foliage was of that type. 



Among the leaves referred to Medullosa and its associates, the most 

 abundant and conspicuous are those described under the great frond 

 genera Neuropteris (fig. 18) and Alethopteris {A. lonchitica is probably 

 the leaf of M. anglica), all of whose species probably belong to Cycado- 

 filicales (82). These frond genera, along with Odontopteris and 

 Didyopteris, are often grouped as the frond family Neuropterideae, 

 and are thought to be generally seed-bearing. The leaves are very 

 large, several times pinnate, and with ovate or oblong leaflets. Their 

 petioles, often of great length and repeatedly branching, have been 

 described under the form genus Myeloxylon, the structure being very 

 much like that found in cycads. 



One of the largest of the frond genera, including many of the 

 most striking of the carboniferous "fronds," is Pecopteris. Through 

 the researches of Grand 'Eury (52) it is known that one of the species 

 (P. Pluckenetii) is seed-bearing; and the sporangia (as Dactylotheca, 

 for example) borne by other species are probably the microsporangia 



I As many tree ferns are very spiny, the presence of spines in Lyginodendron cannot 

 be used as evidence of a climbing habit. 



