MBSOZOIC PLANTS OF NORTH CAROLINA. 113 



Pterozamites gracilis. 

 Plate LIV, Fig. 5. 

 Emmons's "Am. Geol.," p. 118, fig. 86. 



"Frond tapering very gradually to the apex, leaflets oblique to the midrib, linear 

 rounded, and obtuse at their extremities. The frond is about 5 inches long, and in 

 this, as In most of the species, they [the leaflets?] stand nearly opposite to each other. 

 This plant resembles Zamia taxina, but is more delicate." 



It is clearly only a smaller form of the preceding or Ctenophyllum 

 Braunianum var. /3. No locality and no horizon are given for it by 

 Emmons, but it is to be presumed that it occurs with the preceding plant. 



Fterozamites obtusus. 



Plate LIV, Fig. 1. 



Emmons's "Am. Geol.," p. 119, fig. 86a. 



"Frond very obtuse; stem slender; leaflets distinctly nerved, and rather nar- 

 rowed towards the base. The leaf has about 16 or 17 nerves, and they preserve these 

 [their t] lengths to the apex of the stem, which gives it an obtuse or broad termina- 

 tion. It occurs at House's Quarry." 



This plant is a Ctenophyllum of the type of Ctenophyllum imbricatum 

 (Ett.) Schimp. from the Lias of Steierdorf, Banat. It is, however, a larger 

 plant, and is most, probably a new species. I would have no hesitation in 

 uniting it with the Pterophyllum robustum of Emmons, to be described 

 presently, but for the notable difference in the number of nerves in the 

 leaflets, 16 or 17 in this plant, against 8 or 9 in the case of the P. robustum. 

 It is possible that Emmons may have mistaken the number of nerves in 

 the latter, for sometimes, in certain modes of preservation of the leaflets, 

 and perhaps in their original form, nerves which normally appear distinct 

 are consolidated so as to give a number of strong nerves equal to half the 

 number of the normal finer nerves. This would seem to be the explana- 

 tion of the variable number of nerves seen in Ctenophyllum Braunianum, 

 viz., 6 or 7 fine nerves, and sometimes only 3 strong ones. As we cannot 

 be certain about the nerves of this plant, it will be best to retain it as a 

 distinct species, with the name Ctenophyllum Emmonsi. 



8f 



