SOME FERNS FROM THE CARBONIFEROUS FORMATION. 155 



of the rachis, but its position there is accidental. The surface of the rachis is 

 finely striated. 



Specimen from Cove Shore, east of Cove Harbour, Berwickshire, collected by 

 the late Mr R. Gibbs (Plate VIII. fig. 13), in the Collection of the Geological 

 Survey of Scotland. This specimen, which is preserved in a hard micaceous 

 sandstone containing many vegetable fragments, shows probably a primary 

 dichotomy of the rachis. Before the pinnule segments are reached, there also 

 appears here a threefold diohotomy of the axis, similar to that shown in fig. 12. 



Except the main axis, the other portions of the specimen are indifferently 

 preserved. The rachis is very distinctly striated longitudinally, and seems to 

 have been originally flat, with a well-pronounced central angular ridge, probably 

 representing the vascular system of the rachis. The portion of the rachis 

 shown in this figure is so flat that it must be described as winged. In fact, 

 the frondose expansion of the barren pinnae seems to be only a further develop- 

 ment of this wing. 



Specimen from Long Craigs Bay, near Dunbar, Haddingtonshire, collected 

 by Mr James Bennie (Plate VIII. fig. 14), in the Collection of the Geological 

 Survey of Scotland. This example of a fruiting portion of the frond of A. 

 convoluta from Long Craigs Bay is preserved in a fine-grained red shale. The 

 main rachis and those springing from it are broadly winged, the vascular 

 bundle appearing as an angular ridge running in the centre of the rachis. 

 The lateral pinnae, of which only the basal portions are preserved, are best 

 seen to the right of the figure, and consist of a series of dichotomously divided 

 helicoid segments. The segments of these pinnae overlap each other, and 

 produce an almost inextricable confusion of convolutions. 



Specimen from River Tweed, about 100 yards below Norham Castle, Northum- 

 berland (PI. VIII. fig. 15). This specimen probably exhibits the ultimate divisions 

 of the fertile pinnae, and a comparison of this figure with the fruiting examples 

 Triphyllopteris Collombi, Schimper, figured in the Handbuch der Paleontologie, 

 p. 144, fig. 87, and with the figures of Cyclopteris Acadica given by Dawson, 

 in the Fossil Plants of the Loiver Carb. of Canada, plate vii., will show the great 

 similarity between certain portions of these three ferns. The rachis in this 

 part of the pinnae can scarcely be said to be winged, though distinctly flattened. 



Horizon. — Calciferous Sandstone series. 



Localities : — 



Scotland — Berivicksliire. — Cove Shore, \ mile east of Cove Harbour, 1^ miles 

 north-east of Cockburnspath. " In a hard bed of micaceous sandstone at 

 the base of the Carbonificerous Rocks, or rather at the base of that 

 portion of them which immediately overlies the red and yellow sandstones of 

 Berwickshire"* (R. Gibbs, collector) Kimmerghame Quarry, near Duns ; (A. 

 Macconochie). Haddingtonshire. — Long Craigs Bay, east of Belhaven Bay, 



* "Memoirs of the Geol. Survey of Great Britain," The Geology of Eastern Berwickshire, p. 58, 1864. 



