27J? pboceedings of the geological society. [Mar. 22, 



18 inches in length, and 3^ inches in average breadth. The exposed 

 side shows about twenty-two large leaf-scars arranged spirally. 

 Each leaf, where broken off, has left a rough fracture ; and above 

 this is a semicircular impression of the petiole against the stem, 

 which, as well as the surface of the bases of the petioles, is longi- 

 tudinally striated or tuberculated. The structures are not pre- 

 served, but merely the outer epidermis, as a coaly film. The stem 

 altogether much resembles Caulopteris PeacJiii, but is of larger size. 

 It differs from C. Lockwoodi in the more elongated leaf-bases, and 

 in the leaves being more remotely placed; but it is evidently of 

 the same general character with that species, 



\ / 3. Caulopteeis (Pkotopteeis) peregkina, Newberry, 



(Plate XII. fig. 5 and 6.) 



This is a much more interesting species than the last, as belong- 

 ing to a generic or subgeneric form not hitherto recognized below 

 the Carboniferous, and having its minute structure in part pre- 

 served. 



The specimens are, like the last, on slabs of marine limestone of 

 the Corniferous formation, and flattened. One represents an upper 

 portion of the stem with leaf-scars and remains of petioles ; another 

 a lower portion, with aerial roots. The upper part is 3 inches in 

 diameter, and about a foot in length, and shows thirty leaf-scars, which 

 are about | of an inch wide, and rather less in depth (fig. 5, a). The 

 upper part presents a distinct rounded and sometimes double mar- 

 ginal line, sometimes with a slight depression in the middle. The 

 lower part is irregular, and when most perfect shows seven slender 

 vascular bundles, passing obliquely downward into the stem. The 

 more perfect leaf-bases have the structure preserved, and show a 

 delicate, thin-walled, oval parenchyma, while the vascular bundles 

 show scalariform vessels with short bars in several rows, in the 

 manner of many modern ferns. Some of the scars show traces of 

 the hippocrepian mark characteristic oi Protopteris ; and the arrange- 

 ment of the vascular bundles at the base of the scars is the same as 

 in that genus, as are also the general form and arrangement of the 

 scars. On careful examination, the species is indeed very near to 

 the typical P. Sternbergii, as figured by Corda and Schimper*. 



The genus Protopteris of Sternberg, though the original species 

 (P. punctata) appears as a Lepidodendron in his earlier plate (pi. 4), 

 and as a Sigillaria {S. punctata) in Brongniart's great work, is a 

 true tree fern ; and the structure of one species (P. Cottai) has 

 been beautifully figured by Corda. The species hitherto described 

 are from the Carboniferous and Permian. 



The second specimen of this species represents a lower part of the 

 stem (fig. 6). It is 13 inches long and about 4 inches in diameter, 

 and is covered with a mass of flattened aerial roots lying parallel to 

 each other, in the manner of the Psaronites of the Coal-formatioii 

 and of P. erianus of the Upper Erian or Devonian. 



* Corda, Beitrage, pi. 48, copied by Schimper, pi. 52. 



