388 NEW YORK STATE MUSEUM 
Palaeontologie, p. 739] not only accepted this conception but even created 
a new subfamily, Proscorpionini, which was not brought under the Siluric 
Palaeophonidae, but under the Carbonic Eoscorpionidae, chiefly because of 
the supposed existence of double terminal claws on the walking legs. 
A year later there appeared in the American Naturalist a critical 
review by Thorell, of Whitfield’s interpretation of certain points in the 
organization of the scorpion and Whitfield soon after published in Scéence 
a general denial of all these points. 
When describing the Scottish Siluric scorpion, Pocock in 1901, also 
discussed Proscorpius osborni, obviously unaware of the criti- 
cism by Thorell and of Whitfield’s rejoinder, and raised some of the identical 
points as Thorell, especially in regard to the supposed double claws of 
the walking leg; and subsequently Fritsch published somewhat fuller notes 
from excellent photographs made by Dr E. O. Hovey. Fritsch, too, was un- 
aware of Thorell’s paper, but he fully verifies Thorell’s criticisms. As 
even the best photograph is misleading through the projection of all parts 
into one plane and the appearance of deceptive shadows, a close investiga- 
tion of the specimen itself is essential in order to settle the many debated 
points and by the courtesy of Dr Hovey we have had full opportunity 
to study the specimen and to compare it with his photograph. In con- 
sequence we have added a third figure and a restoration to illustrate 
our conception of the fossil. 
Carapace. This is subquadrate in outline, a little wider than long. 
Its front margin is straight and faintly emarginate, appearing trilobed 
through the projection of the eye lobe in the middle and _ that 
of the frontal lobes at the antelateral angles. The eyelobe is relatively 
large, roundish pentagonal. The frontal lobes are well rounded and pro- 
ject slightly beyond the frontal margin. The left lateral margin is dis- 
tinctly broken and incomplete, and the right one largely covered by 
the matrix; nevertheless the anterior portion of the right margin can be 
distinctly seen to bulge out directly behind the eye lobe, and we have 
no doubt that the carapace was broader in the middle than in front [see 
restoration, text fig. 83]. The posterior margin is slightly concave. The sur- 
face of the carapace is rather even and smooth and a great number of bristles 
