DESCRIPTION OF SPECIES. PP. 101 



incised terminal margin, a grooved petiole, strongly defined, 

 sparingly forked nerves, with branches nearly parallel, and 

 a dichotomous mode of forking which is very character- 

 istic. 



The points of difference which induce us to separate the 

 plant generically from Salisburia are the following : — 



In Salisburia, the basal cord is merely a branching nerve 

 of no more value than its neighbors. This may be plainly 

 seen on the lower surface of the leaf. The woody bundles 

 in the petiole of the leaf divide at the base of the lamina 

 into two principal nerve-bundles, and each of them on en- 

 tering the leaf divides into two principal nerves on each 

 side. These by successive f orkings, in a dichotomous man- 

 ner, till the entire leaf with their branches. The nerve 

 which follows the margin of the leaf has none of the char- 

 acters of a petiole, and does not send out independent 

 nerves, but simply splits up by dichotomy into a succes- 

 sion of branches of equal value, and which all pursue the 

 same general direction with the principal nerve. The char- 

 acter of the forking is the same with that shown in the 

 principal nerves which enter the leaf more towards the 

 center. 



The case is different with the woody border on the fossil 

 plant. This seems to perform the functions of a petiole, or 

 of the rachis in ferns. The mode of departure of the nerves 

 sent off by it, as shown by Fig. la is much like that of the 

 lateral nerves from the rachis of a Tseniopteris. It sends 

 off nerves independent of each other, and not mere branches, 

 produced by the splitting up of a parent nerve. We do not 

 find the branches which enter the lamina, in the fossil leaf, 

 to follow so closely the direction of the marginal woody 

 cord, as do the branches in Salisburia. They even, as shown 

 in Fig. 4, attain a direction at right angles with it. 



We name the genus in honor of Count Saporta, the cele- 

 brated palseobotanist of France. 



Saportaa grandifoUa. Sp. nov., PI. XXXVIII, Fig. 4. 



(Leaf, with a strong woody cord passing around the base, 



and descending into a rather slender, long i)etiole, which 



