﻿I860.] 



DAWSON FOSSIL EEEN. 



5 



2. On an Undesceibed Fossil Feen from the Lowee Coal-Measuees 

 of Nova Scotia. By Dr. J. W. Dawson, F.O.S. 



(Abstract.) 



In a paper on the Lower Carboniferous rocks of British America, 

 published in the 15th volume of the Geological Society's Journal, 

 Dr. Dawson noticed some fragmentary plant-remains which he re- 

 ferred with some doubt, the one to Schizopteris (Brongn.), and the 

 other to Sphcereda (L. and H.). With these were also fragments 

 of a fern resembling Sphenopteris {Cyclopteris) adiantoides of Lindley 

 and Hutton. Since 1858 the author has received a large series of 

 better-preserved specimens from Mr. C. F. Hartt ; and from these he 

 finds that what he doubtfully termed the frond of Schizopteris is a 

 flattened stipe, and that the leaflets which he referred to Sphenopteris 

 adiantoides really belonged to the same plant. Mr. Hartt's speci- 

 mens also lead Dr. Dawson to suppose that what he thought to be 

 Sphceredce were attached to the subdivisions of these stipes, and may 

 be the remains of fertile pinnae, borne on the lower part of the stipe, 

 as in some modem ferns. This structure he regards as being some- 

 thing like what obtains in the Cuban Aneimia adiantifolia, as pointed 

 out to the author by Prof. Eaton, of Yale College. No sporangia 

 are seen in the fossil specimens. 



Dr. Dawson offered some remai'ks on the difficulties of arranging 

 this fern among the fossil Cyclopterides, Noeggerathice, and Adian- 

 tites ; and, placing it in the genus Cyclopteris, he suggested that it 

 be recognised as a subgenus (Aneimites) with the specific name 

 Acadica. 



The regularly striated and gracefully branching stipes, terminated 

 by groups of pinnules on slender petioles, must have given to this 

 fern a very elegant appearance. It attained a great size. One 

 stipe is 22 inches in diameter, where it expands to unite with the 

 stem ; and it attains a length of 21 inches before it divides into 

 branches. The frond must have been at least 3 feet broad. The 

 specimens are extremely numerous at Horton. 



The author then noticed that the long slender leaves so common 

 in the Coal-measures of Nova Scotia, and hitherto called Poacites, 

 though sometimes like the stipes of Aneimites, are probably leaves of 

 Cordaites. 



On some specimens of Cyclopteris (Aneimites) Acadica, markings 

 like those made by insects have been observed ; also a specimen of the 

 Spirorbis carbonarius. 



