4 Devonian Flants^ 



Gasp6 sections in a state of perfection unusual with palseozoie 

 plants. It is characterized by slender, bifurcating, ridged sterns^ 

 proceeding from a horizontal rhizoma, which sends forth numerous 

 rootlets. The rhizomata, evidently in situ, clothe some beds of 

 indurated clay with a mat of creeping and occasionally bifurcat- 

 ino- cylindrical stems, filling the beds below with their vertical 

 rootlets. They attain a diameter of an inch or more, though 

 usually smaller, and a length of at least three feet. They are irre- 

 gularly dotted with minute linear punctures, the marks probably 

 of ramenta ; and at intervals there are circular areoles with central 

 pits, like those of Stigmaria, but irregularly disposed, and giving 

 origin to the roots, which, however, unlike those of Stigmaria, 

 subdivide in descending into the soil. Apart from the stems, 

 these rhizomata might be included in the genus Karstenia or 

 Halonia, or even as abnormal species in Stigmaria (iig. 1 a,). 

 The aerial stems vary from a fourth to a tenth of an inch in 

 diameter at their origin, rise obliquely from the rhizoma, and 

 bifurcate very regularly. The extreme points divide nearly at 

 rit"^ht angles, and in some, probably young, branches the ultimate 

 branchlets bend into a spiral curve with a somewhat unilateral 

 arrangement of the leaflets. In the shale overlying the small 

 coal-seam above-mentioned, there are immense numbers of these 

 little branchlets, rolled so closely as to resemble spiral shells 

 Thev probably indicate a circinate vernation like that of ferns. 

 (See figs. 1 h, c, d) The surface of the stems is very smooth and 

 glossy, quite destitute of scars, but marked with numerous inter- 

 rupted ridges spirally arranged, and sometimes seen to project a 

 little at the upper ends, as if rudimentary leaves. This leaf-like 

 character is more distinct toward the extremities of the branches; 

 but the leaves are not sufficiently well preserved to show anything 

 more than that they are slender and acicular. 



The greater part of the specimens are flattened, with the epider- 

 mis alone preserved in a coaly state ; but a few fragments were 

 found with the internal structure remaining. It consists of a 

 slender axis of scalariform vessels, surrounded by a space now 

 occupied by calcspar, but showing in parts the remains of a loose 

 cellular tissue. Externally to this is a cylinder of well-preservedy 

 elongated, woody cells, without distinguishable pores, but with 

 traces of very delicate spiral fibres. (Fig. 2 g, h^ i, k.) 



The structure and external appearance above described indicate 

 affinities with the Lycopodiacem^ and especially with the genus 



