﻿HEER ON THE ANTHRACITE PLANTS OF THE ALPS. 101 



Agrees in all respects with the Coal-plant, except that the pinnules 

 are slenderer. 



(Aus.) 17- Cyatheites polymorphic, Brongn. sp. 

 Erbignon. 



18. Alethopteris Brongniarti, Gopp. (Pecopteris pteroides, 



Brongn.) 



Seems to be the most abundant Fern in La Mure. In some cases 

 the edges of the leaflets seem to be rolled up, as in Pteris. 



19. Pecopteris Pluckenetii, Schl. sp. 

 Col de Balme. 



The Basle Museum possesses a splendid fragment of the lower part 

 of the frond from this locality. From the stem, which is stout, run 

 long pinnae standing pretty close together, so that the leaflets of ad- 

 joining pinnae partly cover each other. The pinnae are divided into 

 a great number of secondary pinnae (twelve can be counted on each 

 side of an imperfect pinna, wanting its summit) ; each of these is 

 pinnated with six to eight lobes, which are united at the base and 

 obtusely rounded. This precisely agrees with the upper two pinnae 

 in tab. 107. fig. 3 of Brongniart. In our collection we have a beau- 

 tiful stem from the Coal-measures of Zwickau which answers to the 

 lower pinna of the same figure. 



(*)(f)20. Pecopteris pulchra, Heer. 



Fronde bipiimata, pinnis pinnulisque patentibus remotis; pinnulis distantibus 

 oblongo-lanceolatis, basi apiceque obtusis integerrimis ; nervo medio excur- 

 rente, nervis secundariis sub angulo acuto egredientibus. 



Petit-Cceur ; a well-preserved specimen procured by Escher. 



The stalk is moderately thick. The pinnae stand pretty wide 

 apart, so that their edges do not touch. The pinnae are not very 

 long ; their middle pinnules are longer than those at the base or 

 point of the pinnae. The pinna-stalk is thin, the leaflets alternately 

 arranged on it, but yet so that they are in pairs. These leaflets are 

 so far apart, that their edges do not touch, and even a considerable 

 interval is seen between them. Some stand at a right angle to the 

 stalk, and others at a slightly acute angle. They are longitudinally- 

 lanceolate, a little wider at the base than across the middle, and ob- 

 tusely rounded at both ends. They are from 4"' to 4£"' long, and 

 from 1"' to lj'" wide. The venation is generally obliterated; but 

 sometimes the midrib can be traced to the point of the leaflet, and 

 delicate secondary veins branching obliquely from it. These are 

 easily distinguished from the lower pinnae of Neuropteris Escheri, 

 which occur on the same stone, by their more slender shape, and 

 from Cyatheites Schlotheimii by the pinnae being much shorter, and 

 by the leaflets being longer, slenderer, and further apart. They agree 

 best with that subdivision of Pecopteris with pinnated fronds and 



