656 ME. J. STAEKIE GABDNEB ON EOCENE EEBNS FEOJI 



I am afraid, from a botanical aspect, that their interest is not 

 great ; but, geologically, they supply data of considerable value 

 towards fixing the relative age of one of the most remarkable 

 formations in the world, and not less important because entirely 

 destitute of fossil remains save and except plants. I allude to 

 the enormous basaltic formation of the North-east Atlantic, which 

 once stretched, there is every reason to believe, continuously from 

 Antrim through the Faroe's and Iceland to Greenland. 



Gleichenia iiibeenica, sp. nov. (Plate XXVI. figs. 5-7.) 



Eocene basalts, Glenarm and Ballypalady, County Antrim. 



Pinnae narrow oblong, acuminate, with probably entire and even 

 caudate apices, length 10 centim., breadth 4 centim., cut down 

 within a short distance of the rhachis into numerous linear lobes, 

 30 millim. in extreme length and 5 to 6 millim. broad. The lobes 

 are at angles of 50° to 60° with the rhachis, obtuse or subacute, 

 opposite near the base and alternate higher up the pinna. Eha- 

 chis prominent, slender, glabrous ; primary veins of the segments 

 undulating, directed alternately towards each bundle of veinlets. 

 The lowest veinlets fork once and extend to the margin of the 

 sinus. The veinlets are fine and grouped in fasciculi, simple at 

 first and starting at an angle of 55°, they divide into 3, the outer 

 simple and the central one forked ; though sometimes two, at 

 times all three of the veinlets fork. The venation becomes more 

 simple towards the apices. The margins of the segments seem 

 faintly undulate. The species seems to have been rigid, and the 

 texture coriaceous. Below the last segment is a small ear-like 

 expansion in one of the specimens, destitute of midrib but 

 traversed by forked veinlets. 



The soriwere removed before the pinnae became imbedded, but 

 their position is defined by a small narrow elliptical scar, situated 

 near the base of the most forward— that farthest from the midrib 

 — of the secondary veinlets of each fasciculus (fig. 7), though 

 where these are more complex, near to the bases of the pinnules, 

 the scars occur on both the outside veinlets instead of on one. 

 Their position leaves no doubt as to the genus in which the fossil 

 should be placed, and the whole habit agrees with the Mertensia 

 section of Gleichenia, and especially with G. dichotoma, a native, 

 according to Sir W. Hooker, " of tropical and subtropical regions, 

 almost universal in the New and in the Old Worlds, Pacific 



