FOSSIL PLANTS. 421 



GENUS SPHENOPHYLLUM, Brongt. 

 SPENOPHYLLUM CORNUTUM, Sp. nov. 



PL xix, fig. 1 to 5. 



MAIN stem round, half an inch broad, articulate at equal 

 distances (about one inch), inflated at the nodi or points of in- 

 sertion of the whorls of leaves, smooth but obscurely ribbed 

 in the length, divided about at right angles by long straight 

 branches bearing whorls of five or six leaflets, joined at the 

 base ; leaflets equal, fan-like in outline, broadly cuneiform to the 

 base, divided from below the middle into seven to nine linear, 

 pointed, nearly equal lobes ; veins distinct, flat, four to five at 

 the base of each leaflet, forking once, each division ascend- 

 ing to the top of one of the lobes (fig. 5 enlarged) . 



It is a well characterized and distinct species, and in studying it at Colches- 

 ter, I have found among the shales a great number of broken specimens, rep- 

 resenting different parts of it, and have seen all the leaflets, from the 

 largest one around the broad part of the stems, to those of the branchlets, pre- 

 senting the same form and kind of division. It can be compared only to a 

 variety of Sphenophyllum emarginatum, Brgt., figured by Geinitz in his Verst. 

 pi. xx, fig. 6. But it differs indeed in its essential characters: broader stems 

 and leaflets, peculiar and equal divisions, and a different kind of nervation. 

 The branching, as seen, fig. 1, is also peculiar for a species of this genus. It 

 is worth remarking that the branches of this plant are mixed on most of the 

 specimens with the remains of a somewhat obscure Calamites, resembling Cata- 

 mites Suckowii, Brgt , a coincidence which may be casual. In any case I could 

 not trace any evident connection between the two plants, and the stems of this 

 SphenophyUum do not appear as equally and deeply striate as are generally the 

 branches of Calamites. 



Hoof shales of the Colchester coal. 



