406 MR B. N. PEACH ON SOME 
thin and wrinkled. The only portions of the carapace usually exposed are the 
thickened raised mounds, and it is only in one or two out of over thirty speci- 
mens in the Survey Collection that the posterior portion of the carapace is 
preserved. 
Observations.—The appearance of the above fossil when filled in with caleuli 
is much like a gigantic ostracod, and bears a great resemblance to Beyrichia, 
though the test, where not destroyed by calculi, exhibits under the microscope 
the characters borne by that of spiders and insects. By treating those that 
are most destroyed by calculi with hydrochloric acid the calcareous matter can 
be dissolved out, and as the test is not soluble, the portions not entirely split 
up still exhibit structure. It is just possible that this is not a portion of a 
scorpion, but that it is referable to the genus Cyclus (de Koninck), undoubted 
species of which occur in the same beds with the above fossil and with their 
tests similarly infested. It may be as well to mention that almost all the fossil 
scorpions in the Survey Collection have the horny substance of the test 
still preserved. It is elastic, of a brownish-red colour and slightly transparent, 
and seems to have undergone very little alteration. It is quite imsoluble even 
in strong hydrochloric acid,—-a useful character, as it allows the specimens to 
be cleaned for microscopic examination. , 
Disjecta Membra.—Among the fragments that cannot with certainty be 
referred to any known species, there are many specimens that help to clear up 
points in the morphology of these ancient scorpions. Combs often occur, and 
it is afortunate circumstance that they are so easily recognisable and so charac- 
teristic. Figs. 16 and 16a represent a portion of one, both natural size and 
enlarged, showing the nature of ornament like irregularly dropping embossed 
scales, reminding one very much of that on Hurypterus and Pterygotus. A 
few of the teeth which fringed the lower edge are still preserved. This 
specimen comes from the rich bed near Langholm. Several combs are found 
among the fragments from the Calciferous Sandstone near Edinburgh. 
The abdominal plates are also frequently obtained. Fig. 17 represents. 
one from the ventral surface (natural size), with the combs pressed through it. 
This probably belongs to L. tuberculatus, several carapaces of which have been 
obtained from the same beds near Cramond. Walking legs are not uncommon. 
Fig. 6 is a copy of an almost perfect one from Coldstream, Berwickshire, from 
the Cementstone group (Lower Carboniferous). Some fragments of the walk- 
ing legs from Berwickshire are very large, being over two inches long and 
one third of an inch wide in their flattened state, showing to what a large size 
some of these old scorpions must have attained. Fig. 4 shows the tarsus and 
manus of one (natural size) from the well-known locality of Lennel Braes, 
River Tweed, near Coldstream. The spines and movable terminal hooks are 
well shown. This must have belonged to a very large individual. Fig. 5 
