SELLARDS: PERMIAN PLANTS. 7 



on Nilssonia polymorplia Schenk are described as small, situated at 

 approximately regular distances apart, between the veins. The 

 dots of this species have been variously regarded by different 

 authors. Schenk regarded them as the remains of sori and accord- 

 ingly referred the genus to the ferns. ' Saporta considered them 

 more like fungi and referred the genus again to the cycads. - 

 Count Solms Laubach, P'ossil Botany, p. 140 (Balfours transla- 

 tion), in summing up the evidence considers Schenk's view more 

 probable than Saporta's, and therefore treats of the genus among 

 the ferns. Later authors have generally referred the genus to the 

 cycads. Another interesting point of analogy between those spec- 

 imens of JSilssonia polymorplia having unsegmented pinnae and the 

 Taeniopterids under consideration is the striking similarity in the 

 shape and venation of the apical part of the frond. In both the 

 midvein is reduced to a mere line, but continues to the apex, the 

 lateral veins are arched upwards, with numerous dots between 

 them. 



Neuropteris. 



A specimen of Neuropteris in the Lacoe collection of the United 

 States National Museum, which Dr. White had the kindness to 

 show me, has dots between the veins very suggestive of the oval 

 bodies between the veins of our specimens of Tacnioptcris. Dr. 

 White is inclined to regard these dots as glands. The species is 

 described in an unpublished manuscript of Lesquereux, which Dr. 

 White is now editing. 



Alethopteris. 



Andrews described in Vol. II, paj. Geol. Surv. of Ohio, p. 421, 

 pi. 50, figs. 3-3b, a species from near the base of the coal measures 

 of Ohio,^under the name Alethopteris maxima And., which has nu- 

 merous small dots between the veins-. Andrews regarded these as 

 probably dots of iron oxide. Lesquereux, Coal Flora, p. 187, re. 

 fers to them as "remants or the base of scales similar to those often 

 seen upon leaflets of species of Acrostiehiim.''' 



Megalopteris 



Dots occur between the veins of J/. Harttii And. and J/, dentata 

 in the museum collection, from Rushville, Ohio, ver}' like those 

 on Taeniopteris. 



I Die fossilc Flora dor Urfiizscliiclitoii (Ins Kcupirs iiri<l Lias 1' ran kens, ISCiS. 

 i I'aleontoloj^ie fraiK'aiso, s(\r. :.', vcfiiMaux, vol. :.', ls7."). 



