414 



ON SPECIES OF FOSSIL PLANTS 



wedge-form at the base or narrowed to the long thick petiole, and wavy crenate on the 

 borders. 



6. Salix WoRTHENJI, Spec, no v. PL xv, Fig. 7. S. foliis in petiolura sensim attenuates, exaote lanoeolatis 

 aeutis, margine integerrimis, norvo medio anguato, nervis secundariis graeilibus, nuraerosis, sub angulo latiore 

 exeuntibus, valde curvatis, alternatim brevioribus, camptodromis. 



Soft white clay. La Grange, Tennessee ; Mound City, Illinois. 



The leaf here figured under the above name was communicated to me by Prof. A. Ii. 

 Worthen, State Geologist of Illinois. A second, with the same shape and the same nerva- 

 tion, only smaller, was sent by Prof. James Safford, from La Grange, Tennessee. 



The leaves of this willow are exactly lance-shaped, equally narrowed toward the point, 

 and the petiole proportionally broad and short. The nervation is distinct, though the 

 secondary nerves are thin. These come out of the medial nerve in an open angle and, 

 from the middle, curve strongly upwards along the borders. Alternately shorter and 

 longer, the shorter ones divide by vcinlets, and anastomosing with branches of the long 

 ones, they form a reticulation of pretty large square or polygonous areas. 



I do not know of any living species which this one resembles. Its nearest relatives 

 among fossil plants are, for the form of the leaves, Salix Integra, Gopp., and for the nerva- 

 tion, Salix tenera, Al. Braun, both from GLningcn. Indeed, it should be considered as 

 identical with this last species, if, according to Prof. Hccr's remarks, its leaves are some- 

 times taper-pointed and narrowed, not only toward the point but toward the base. Fig. 

 10, PI. lxviii, of Heer's Flor. Tert. Helvet., approaches this form, but our leaves are pro- 

 portionably shorter and still more exactly lanceolate. 



7. Salix tabellaris, Spec. nov. PI. xvii, Fig. 4. S. foliis elongatis, ultra pollicaribus latis, linearibus, 

 margine parallelis, integerrimis, in petiolum attenuates; nervo medio lato, nervis secundariis nutnerosis, irregulari- 

 bus, angustis, camptodromis. 



Soft white clay. 



The leaf appears short petioled. From the width of the medial nerve, and from its 

 gradual decrease up to the broken point, the blade of the leaf is at least twice as long as 

 the preserved part of the specimen. The borders are exactly parallel and entire; ; the sur- 

 face smooth, apparently shining. The secondary nerves are irregular, generally long ones, 

 curving along the margins, alternating with short ones, or sometimes coming out of the 

 medial nerve in various angles of divergence. 



Except that the leaves are broader and the borders exactly parallel, our species would 

 appear identical with Salix longa, Al. Braun, from (Eningen. As Salix angusta, Al. 

 Eraun, also from (Eningen, may be, according to Prof. Iieer, a mere variety of Salix longa, 

 though its leaves are narrower, our species might be as well considered as a variety with 



