NEW SPECIES OF FOSSIL SCORPIONS. 407 
is the tarsal joint of a still larger one, but even the owner of this must have 
been small compared with the scorpion to which the penultimate joint of the 
Palpus represented in fig. 18 (natural size) belonged. Fig. 20 is a drawing of a 
tail segment from Cramond which shows the articular surface on the anterior 
portion, the longitudinal ridges, and the abruptly truncated posterior margin. 
The only portion referable to the poison gland is a specimen represented by 
fig. 21. It is ovoid in shape, and has its articular surface placed not symme- 
trically but slightly on one side. It is unfortunate that at the very place 
where the sting should be, an ostracod shell (Leperditia) interferes with the 
specimen. The line of the ventral margin is seen beyond this, but soon 
becomes lost. A harder portion of the test of a scorpion is seen where the 
sting should be were it present, but it would not be safe to say definitely that 
it was the sting itself, however much it might suggest its being such. The 
poison gland of a recent American scorpion is drawn in fig. 22 for comparison. 
Figs. 18a, 180 show the microscopic structure of the test of the specimen 
represented in fig. 18. It is composed of two layers, the upper surface 
being made up of a network of hexagonal cells. Irregularly placed depres- 
sions are found at intervals, and these sometimes pass through both layers. 
In other instances they are merely dimples as it were in the test. When the 
test supports hairs each always rises out of the centre of such a depression 
(fig. 18a). The tuberculations seem to be very irregularly disposed over the 
test of such species as exhibit them. The movable claws of &. glaber do not 
seem to be serrated on the lower edges, while those of the foot from Lennel 
Braes (fig. 4) appear to be notched. Fig. 18¢ represents the magnified mus- 
cular bundles found in the joint of the specimen (fig. 18). 
The disjecta membra show that there must be several species of scorpion in 
these Carboniferous rocks besides those which have been found sufficiently 
complete to show specific characters, a fact that should incite local geologists 
to search for them. That they are not rare, may be inferred from the fact 
that nearly one hundred fragments have been got by the Survey collectors from 
several widely separated localities and horizons since the year commenced. 
The type specimen of £. carbonarius for which Messrs MEEK and 
WorTHEN made the genus, unfortunately did not exhibit any of the organs on 
which generic classification usually proceeds.* The consideration of the pre- 
sent collection puts us in a better position, and while retaining their name I 
would propose the following characters as being distinctive of the genus. 
* Vide Messrs Merk and Wortuen’s description in the ‘“ Memoirs of the Geological Survey of 
Illinois,” vol. iii. pp. 560-562. Figs. 23 to 230 are a reproduction of the woodcut accompanying their 
description. 
