1862.] DAWSON — DEVONlAIf PLANTS. 313 



collections from ISTew York State, where the species occurs in the 

 base of the Catskill group and in the upper part of the Hamilton 

 group. The varied aspects of the species presented in the numerous 

 specimens thus submitted to me would, with a less perfect suite of 

 examples, afford grounds for specific or even generic distinctions. 

 Mattened specimens, covered with bark, present contiguous, elliptical, 

 slightly elevated areoles, with an indistinct vertical line and a small 

 central vascular scar (fig. 58). Decorticated specimens, slightly 

 compressed, show elliptical depressed areoles, not contiguous, and 

 with only traces of the vascular scars (fig. 26). In more slender 

 branches the areoles are often elevated at one end in the manner of 

 a Knorria (fig. 28) ; and in some specimens the areoles are indistinct, 

 and the vascular scars appear as circular spots, giving the appearance 

 presented by the plants named Cydostigma by Haughton (fig. 27). 

 All these forms are, however, merely different states of preservation 

 of the same species. 



This plant is closely allied to L. nothum, linger, but differs in its 

 habit of growth and in the size of the areoles relatively to that of 

 the branches. The branches were long and slender, bifurcating 

 rarely, and, unless they were very woody, must have been pendent 

 or decumbent. ISTo large trunks have been seen. It was a widely 

 distributed and abundant species in the Upper and Middle Devonian 

 Periods. The plant figured by Prof. Eogers in the ^Eeport on 

 Pennsylvania,' p. 829, fig. 677, can scarcely belong to any other 

 than this species ; and it is also figured in Yanuxem's * Eeport on 

 New York,' p. 191, fig. bb, and p. 157, fig. 38. 



24. Lepidodendeon Chemtingense, Hall. 



HaU's ' Eeport Geol. ISTew York,' p. 275, fig. 127. 



Decorticated stem covered with oval, acuminate, scale-liJce areoles, more 

 acute and smaller in proportion to the size of the stem than in 

 L. Gaspianum. 



The only specimen I have seen is a c^irved branch, very well 

 figured in Prof. Hall's ' Eeport on the Geology of New York,' p. 275, 

 fig. 127. It is a Knorria state of a Lepidodendron or Sagenaria, of 

 more robust growth than L. Gaspianum, but with smaller areoles. 

 It much resembles a decorticated branch of L. elegans of the Lower 

 Coal. Goeppert includes it in his protean species Sagenaria Velthei^ 

 miana, but it does not correspond precisely with any of the forms 

 figured by him. I think it best, therefore, to retain Prof. Hall's 

 specific name, until better specimens shall enable a satisfactory com- 

 parison to be made. Its locality is Elmira, Kew York, and its geo- 

 logical position is the Chemung group. 



25. LEPrDODENDRON coEiiTjGATtrM:, Dawsou. PI. XII. fig. 10. 



Dawson, Quart. Joum. Geol. Soc. vol. xv. p. 68, fig. 2. 



Areoles elliptical, distant, and separated hy a flat surface of corru- 

 gated harlc. Vascular scar central, oval, or linear. 



In Prof. HaU's collection are specimens from the Chemung and 



