DESCKIPTION OF SPECIES— LYCOPODIACEiE. 47 



the base, but generally directed toward both sides, are so exactly of the same 

 character as those of the branches of plate Ixi, figs. 12 and 14, that one can 

 but consider these fragments as representing the same kind of vegetable, its 

 stem and some of its divisions. The branches are slender, variable in length, 

 from one to three centimeters long, linear, five to ten millimeters broad, with 

 a very narrow rachis; the leaves distichous, nearly at right angles to the 

 rachis, are narrowed to the base, lanceolate-pointed, and slightly falcate, 

 generally close to each other, and often imbricating at the borders, without 

 trace of middle nerve; the substance is membranaceous and pellucid, of straw 

 color. A.S seen in fig. 15, some of the branches seem to come in fascicles out 

 of fragments which appear half decomposed, perhaps the bark of the stem 

 stem or a casual agglomeration. 



The characters of this remarkable plant do not fully correspond to those 

 of Selaginella. Its divisions are not distinctly dichotomous, as seen in figs. 

 12 and 13 of plate Ixi, and the leaves are without trace of a middle nerve. 

 The form and position of the leaves might suggest its reference to some 

 peculiar species of Conifers, but the membranaceous pellucid leaves, without 

 middle nerve, as well as the very slender rachis, are against a reference of 

 this kind. It might perhaps represent some peculiar new type of floating 

 Fern. The fragments are very numerous, perfectly distinct; the characters 

 of the plant are exactly represented by the figures. 



Habitat. — Point of Rocks, Wyoming {Dr. F. V. Hayden, Wm. Glehurn). 



Selaginella laciiiiata, Lesqz. 



Plate LXIV, Figs. 12, 12 o. 



Selaginella laciniaia, Lesqx., Annual Report, 1874, p. 297. 



Branches and subdivisioDS like those of the former species, leaves (?) deeply laciuiate ; lacina>i 

 linear, slightly inflated towaid the point, either simple from the base or dichotomous. 



By their mode of vegetation and the form and division of the pinnae or 

 branchlets, these plants are exactly similar to those described above, and 

 indeed they seem to represent the same species under different forms. The 

 difference is in the laceration or thread-like lacinias of the leaflets. These 

 laciniae, distinct and in relief upon the stone, resemble the veins of Fern 

 leaves, when, by maceration and decomposition, the epidermis has been 

 destroyed, and the skeleton of the leaves only is left. In this case, the 

 thread-like branches are not equally and normally divided like veinlcts, but, as 



