CRUSTACEA AND ARACHNIDA OF THE CARBONIFEROUS ROCKS. 519 
gical Survey, while searching the Calciferous Sandstone beds near Cockburns- 
path, a few miles to the south of Dunbar, alighted on a peculiar fossil which 
SALTER described as a new cycadeous plant, under the name of Cycadites 
Caledonicus. For a long time this specimen remained unique. Last spring, 
however, Mr. Macconocuir, while examining the beds in which the famous 
Lennel Braes fossil wood occurs, had the good fortune to find magnificent 
specimens of a like fossil, which proves to be the “comb ” organs of an animal 
nearly allied to scorpion. If my dear old friend and instructor had enjoyed 
the opportunity of studying the new fossils instead of the one he did, which is 
preserved in coarse sandstone, there is little doubt he would have seen that 
they belonged to a Eurypterid, and would have ascribed them to their true 
position in that animal. Fragments of these comb-like organs with Eurypterus 
markings have since been found near Langholm; and this year THomas STock, 
Esq., of the Museum of Science and Art, Edinburgh, has generously allowed me 
to study a small one from the Calciferous Sandstones of Tweeden Burn, Liddes- 
dale, which he got there during a visit he paid to the Borders last year, and 
which he has since presented to the Geological Survey. Professor A. GEIKIE 
has kindly brought me the original specimen of the Cycadites Caledonicus from 
the Jermyn Street Museum, London, for my inspection, and after carefully com- 
paring it with the Lennel Braes fossils, I have little hesitation in looking upon 
it as belonging to a smaller individual of perhaps the same species. I therefore 
retain SALTER’S specific name. 
Description.—Carapace unknown. It was probably semicircular, with sub- 
central simple eyes like those of Hurypterus Scouleri, Hibbert. 
Of the limbs only fragments are preserved, but these are sufficient to show 
that they have been much more elongated than in the case of the Old Red and 
Silurian Eurypterus. One fragment, probably the shaft of the third joint, 
measures 8 cm. in length by 3 cm. in breadth, without showing any articula- 
tion, and as it is broken off at each end it may have been considerably longer. 
That this was the case can be proved, for the lower articulation is preserved on 
a separate piece of stone, which does not fit on to that on which the larger part 
occurs. This portion of the limb was in all probability laterally compressed, and 
bore a fringe of long elegant leaf-like serrations (figs. 17¢-17c) ; while the body 
of the shaft is beset with the ordinary scale pattern, the scales being much 
elongated in the direction of its length. The distal end of the joint seems to 
be prolonged beyond the articulation with the succeeding one into two 
triangular projections, down the outside of which the serrated margin is 
continued, the apex of the triangles being occupied by a blunt-spine just as in 
other limb-joints to be described. Other portions of equally massive limbs 
occur on the same slab with the above, and these bear similar markings. A 
VOL, XXX. PART IL. 4M 
