SOME FERNS FROM THE CARBONIFEROUS FORMATION. 143 



synangium, lettered a, shows very clearly the union of the sporangia in their 

 lower portions. 



Specimen from Bateinghope Burn, Redesdale, Northumberland (figs. 4 and 

 5a). This small example shows four synangia, lettered respectively a, b, c, d, of 

 which a and b are the two most perfect. Each synangium appears to contain from 

 18-20 sporangia. For about half their length the sporangia are free, but their 

 basal portions are united. The individual sporangia, though now compressed, 

 show a distinct rotundity, and have usually one or two well-marked longi- 

 tudinal ridges. The sporangia must have originally possessed considerable 

 substance, for in the fossil state they are frequently converted into a coaly 

 material, which, from its brittle nature, when the stones containing the fossils 

 are split, commonly causes the free portions of the sporangia to spring from 

 the matrix, only leaving their impressions on the stone. 



Specimen from Lewis Burn, over 200 yards below Lewis Burn Colliery, N. 

 Tynedale, Northumberland (fig. 6), collected by Mr J. Bhodes, in the Collection 

 of the Geological Survey of England. This small slab shows two different types 

 of fern fructification lying side by side. That marked a is a synangium of 

 C. bifida, but the other is evidently the remains of an indusium split into five 

 segments. Unfortunately, very few fragments of this interesting fern fructifi- 

 cation (Qb) have been discovered ; but another, though imperfect example, shows 

 the indusia attached to a rachis in a somewhat similar manner to those of 

 Sorocladus stellatus, Lesqx.* It differs, however, from that species in the 

 larger size of the indusium, and in the frond being apparently bipinnate, at 

 least the small fragment showing these fruits attached to the rachis exhibits a 

 bipinnate disposition of the indusia. I propose provisionally to designate this 

 species as Sorocladus antecedens. The plant I here place in Sorocladus differs 

 from Zeilleria in the fruiting portion being altogether destitute of ordinary foliage 

 pinnules. The few fragments of this species which have been collected come 

 from the same locality. 



Specimen from Burdiehouse, Mid-Lothian, in the " Hugh Miller Collec- 

 tion," Museum of Science and Art, Edinburgh (PI. IX. figs. 16 and 17). This 

 example, which is the original of the small woodcut given by Hugh Miller 

 in the Testimony of the Rocks, Edinburgh, 1857, p. 466, fig. 129, is reproduced 

 here natural size. It shows one of the two main divisions of the frond, and 

 bears about 22 pairs of opposite pinnae. The pinnae on the right of the figure 

 are longer than those on the left, the latter having been situated within the 

 fork of the frond. 



The pinnae are lanceolate, the longer ones bearing about 14 pairs of 

 pinnules, which vary from simple to being divided into 8 linear, single-nerved, 

 simple, or bifid segments, according to their position on the pinnae. The 



* Coal Flora of Pennsyl, p. 328, pi. xlviii. fig. 8. 



