EE IAN (DEVONIAN) PLANTS. 



301 



2. Eqtjisetldes Weightiana, sp. n. (PL XII. fig. 10&P1. XIII.fig.20.) 

 This is a specimen in the same collection with the above. It is 



a cast in sandstone, 6 centimetres in diameter, with nodes from 4 to 5 

 centimetres apart. The surface has a slight carbonaceous coating 

 and is finely tuberculated, the tubercles being very regularly 

 arranged, and representing the bases of very short hairs or bristles, 

 which are seen entering the surrounding matrix. Impressions 

 above the joints appear to indicate sheaths, each of about twelve 

 broad leaves, which are abruptly narrowed and acuminate at the top, 

 and show an indication of a median nerve or rib (fig. 10). The leaves 

 of the sheaths are 1 centimetre broad and 1*7 centimetre long. It 

 would be possible, however, to interpret these supposed sheaths as 

 due to mere plications or foldings of the epidermis ; and in this case 

 the plant may have borne verticils of leaves, of which these sup- 

 posed sheaths may be merely the remains. The first explanation, 

 however, appears more probable ; and, if it is correct, the plant is a 

 true Equisetides, and the present specimen is the first occurrence of 

 this genus in beds older than the Carboniferous. It is to be observed, 

 however, that \Jnger has described from the Cypridina-slates of 

 Thuringia plants of the genera Ealymma and Asteropliyllites (A. 

 coronata) with sheaths at the nodes ; and my A. scutigera, from St. 

 John's, has verticils of scales at the joints, which may represent 

 sheaths. The present species has a remarkable resemblance in its 

 markings and the form of its sheaths to a greatly magnified stem of 

 the modern Equisetum Jiiiviatile, except that the leaves of the sheaths 

 are shorter. 



The species is named in honour of its discoverer. Its essential 

 characters will be as follows : — 



Stem stout, cylindrical or broadly ribbed, surface marked with 

 short hairs or tubercles regularly arranged. Sheaths at the joints, 

 of about twelve leaves, of the general form of those of Equisetum 

 fluviatile. 



The specimen is from the Portage group (Upper Erian) of Italy, 

 New York. 



3. Cyclostigma aefine, sp. n. (PI. XII. figs. 11 & 12.) 



Stem marked with alternate circular leaf-bases or areoles, slightly 

 prominent below, evanescent above, and each with a circular dot or 

 vascular mark. Scars scarcely two millimetres in diameter, and 

 separated by finely corrugated bark, about twice their diameter 

 apart. These markings occur on a stem about an inch in diameter. 

 The Knorria, or decorticated form of this plant, presents irregular 

 waving ridges, produced by the longitudinal confluence of the oblique 

 vascular bundles. 



This plant is the nearest approach to the well-known C. TciltorTcense 

 of Ireland hitherto found in America. It differs chiefly in the more 

 closely placed areoles. It was collected by Mr. Wright, and is from 

 the Chemung (Upper Erian) of Italy, New York. The study of this 

 plant has led me to the belief that Stigmaria eocigua of my Report 

 of 1871 may, when better known, prove to be a new species, allied 

 to the present, and a member of the genus Cyclostigma. 



