422 



ON SPECIES OF FOSSIL PLANTS 



Red shale. 



The long ohovate leaf, narrowed into an obtuse point, and gradually decreasing toward 

 the petiole ; the broad medial and the irregular secondary nerves are the essential charac- 

 ters of this species. The form of the leaves resembles that of Magnolia laurifolia ; but the 

 nervation is different. By the irregularity and the distance of the secondary nerves, and 

 by the shape of the leaves also, our fossil species is related to the living Magnolia umbrella, 

 Lam. ; though distinct enough by the more acute angle of divergence of the secondary 

 nerves, and by the obtuse point. 



27. Magnolia ovaus, Spec. nov. PI. xxi, Figs. 3 and 4. M. foliis brcvi petiolatis, late ovalibus, obtusis, 

 basi rotundatis, abrupte, brevissimo in petiolum decurrentibus, nervo priraario lajvi, ncrvis secundariis campto- 

 dromis, distantibus. 



Red shale. 



In this species the leaves are thin, broad oval, and broadly obtuse, both at the top and 

 at the base, which abruptly descends to the short petiole. The secondary nerves are still 

 more distant than in the former, and not quite so much curved upwards. It is altogether 

 a species of a peculiar type, which does not appear to have any representative in our 

 present flora,* and is not comparable to any known fossil plant. 



28. Magnolia cordifolia, Spec. nov. PI. xxii, Figs. 1 and 2. M. foliis submombranaecis, tcnuibus, late 

 ovatis vel rotundatis, brevi acumitiatis, basi cordato-truncatis, in petiolo crasso abrupto subdocurrontibus, nervo 

 medio lato, nervis secundariis arcuatis. 



lied shale. 



The similarity of this species to our Magnolia cordata, Michx., of the Southern States, 

 is striking. But for the thickness of the medial nerve and of the petiole, an appearance 

 which might be explained by compression in the process of petrification, and for the 

 broader angle of divergence of the secondary, slightly arcuate nerves, the identity of both 

 species could not be denied. The basilar form of the leaves and their general outline are 

 the same, for it is evident, from the direction of the margins near the broken point, that 

 these fossil leaves are also acuminate. These are larger than generally in the living 

 species ; but all our Magnolias bear proportionally large leaves, according to climatic 

 circumstances. The substance of the leaves appears as thin as in the former species. 



29. Asimina leiocarpa, Spec. nov. PI. xv, Fig. 8. A. seminibus oblongo ovalibus, uno apice truncatis, 

 altero acutis, laevibus, pollieem longis, vix semi-latis. 



* Prof. Gray informs me that species of Magnolia with obtuse leaves inhabit Japan; but none of them with 

 such nearly round and large leaves as our fossil plant. 



