MESOZOIC PLANTS FROM KOREA. 43 



owing to the want of the basal portion of the frond in the former 

 and of the apical portion in the latter ; but if Feistmantel's 

 explanation is correct, then their relationship is only a slight one, 

 for he understands his specimen to be a probably three-lobed 

 frond while the Korean species is only two-lobed, the resemblance 

 being solely due to the mode of preservation. 



A similar dichotomization of the frond is also well shown 

 by Phlebopteris (?) d'lchotoma Shirley^^ from the Denmark Hill, 

 Ipswich, Queensland. 



EQUISETALES. 



EQUISETUM, L. 



EQUISETUM USHIMARENSE Yok. 



PI. III., fig. 10. 



1889. Equiselum ushimare7ise Yok. : 1. c. p. 39, pl. XI., 

 figs. 1-3. 



A few fragments of rhizomes of an equisetaceous plant are 

 in the writer's collection. Their breadth varies between 2.5 mm. 

 and 6 mm., with three to four, strong ribs and internodes, 

 2.0-2.5 cm. apart. Tubercles rarely found are ovate in form, 

 measuring 1.8 cm. in length and with no surface markings visible 

 on thier surface. 



A comparison between the present examples and the figures 

 of Prof. Yokoyama's species leaves no doubt about their specific 

 identity. 



1) J. Shikley : Additions to the Fossil Flora of Queensland, p. 24, pl. XV., fig. 2. 



