Page:The Eurypterida of New York Volume 1.pdf/404

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
396
NEW YORK STATE MUSEUM

entirely unable to find. We have also failed to find in this place more than a faint, uncolored impression that is probably accidental. Palaeophonus bears a spine in a corresponding position on the second tarsus, and this fact may have induced Scudder's inference.

Although the presence of the two "claws" on which the separation of Proscorpius from Palaeophonus was mainly based [see Whitfield, p. 183] may be wholly illusory, Proscorpius is nevertheless a good genus. This is evinced by the marginal position of the eye lobe and the greater width and different lateral margin of the tergites. The general form of the carapace and the character of the legs, as far as perceivable, indicate that its closest relationship is with the other Siluric scorpions.

There are still two joints of another leg distinguishable on the left side. The three legs drawn by Fritsch on the right side of the carapace are due to deceptive shadows on the photograph, produced by irregular organic patches that lie in a higher layer of rock and apparently have nothing to do with the scorpion. It is desirable that this covering matrix be removed and a possibly complete right margin of the carapace exposed.

Fritsch was the first to observe the portion of the comb discernible on the left side. The specimen itself shows the fragments still more distinctly than the photograph, because the surface bearing them slants away from the light. Fritsch recognized fulcra and comb teeth and states that these remains indicate that this organ was of similar structure as in the younger scorpions.

The inspection of the specimen in good light has brought out the interesting fact that the test distinctly retains the bristles with which it was covered. They are most distinctly seen, and also thickest, on the carapace, but also visible on the tergites. The photograph fails to show them.

We may be allowed to touch upon the fascinating question of the original habitat of this waterlime scorpion, even though it can not, in the absence of the ventral side, furnish any direct evidence as to its mode of breathing.