206 THE POTOMAC OR YOUNGER MESOZOIO FLORA. 



nut-like seed, that are borne on short pedicels on each side of slender stems, 

 which spring from the main stem like the leaves, and appear to represent 

 metamorphosed leaves. 



This curious group of plants has its single leaves in shape and ner- 

 vation strikingly like those of Jeanpaulia, and in some cases they are 

 much like those of Baiera. Before the more complete specimens were 

 found, showing the mode of attachment of the leaves, I thought that the 

 plants belonged to the genus Baiera. Heer united the plants formerly 

 called Jeanpaulia with Baiera ; but there would seem to be a very consid- 

 erable difference between such a plant as Jeanpaulia Mimsteriana, given by 

 Schenk,^ and Heer's Baiera lougifoUa. The leaves of Schenk's plant appear 

 to be compound, composed of pinnately arranged segments with a terminal 

 segment. The plan of this leaf is mucli like that of the leafy branches of 

 Baieropsis, and it may be a question whether or not this Rluietic supposed 

 leaf is really a leafy branch. There is also some resemblance between the 

 mode of segmentation of Baieropsis and that of the plants which Heer^ 

 called Jeanpaulia horealis, and J. lepida, and which in the fourth volume of 

 the same work he was inclined to think might be ferns. But these two 

 plants have much shorter and proportionally broader lobes than those of 

 Baieropsis. Baieropsis in some points is like Saporta's genus Ginl'ijophjiUunt. 

 In this latter, however, the leaves are flabellately divided only towards their 

 summits and very sparingly segmented, while the greater portion of their 

 length in their lower portions is strap-shaped, and these long strap shaped 

 basal portions unite at their insertions to form a wing along the midrib. 

 Some of the leaves of Baieropsis are in shape much like those of some 

 forms of Adiantum. These might be regarded as Ginkgos, were it not for 

 the pinnate aiTangement of the leaves. 



These forms, which I have united under tue generic name Baieropsis, 

 seem to have more of the characters of the Ginkgo section of broad-leaved 

 conifers. They are most probably nearly allied to Ginkgoplujllum and 

 Baiera, but still in some of the forms fern characters are to some extent 

 present, and so long as the fructification is not clearly made out, the true 

 place of the group can noS be positively determined. 



'foss. Flor. tl. Grenzschichten, PI. IX, Fig. 9. 



=Fo8S. Flor. Arctica, vol. 3, Pt. 2, pp. .W, 58, PI.. II, Fig. 1-15. 



