Srom the Coal-measures of Illinois. 25 
nearly perfect specimens will show it to be typical of a new 
genus. If so, it might be called Hoscorpius, in allusion to its 
early appearance in time. 
Amongst the specimens we have, from time to time, had an 
opportunity to examine from the Mazon creek locality, we 
have frequently observed impressions of a long, many jointed 
fossil, in regard to the true nature of which we 
e to arrive at any very satisfactory conclusion. We could 
hardly doubt but it was an Articulate of some kind, and were 
inclined to believe it a Myriapod, All our examinations, how- 
ever, of the specimens at that time known, failed to quite sat- 
isfy us that what looked like legs projecting out into the mat~ 
rix, were really not rigid, inarticulate spines,* Hence, we were 
left in some doubt, whether or not it might be the mould of 
the vertebral column of some little vertebrate animal; and 
after many careful examinations, we concluded to lay the speci- 
mens aside, hoping that better examples might be found, giving 
some clue to their nature. In the meantime, however, we 
showed all of them we had seen to several of our most eminent 
naturalists, none of whom could give us any suggestions in re-~ 
gard to the affinities of the animal. : 
Several of the specimens now before us, of this same fossil, 
ound last summer by Mr. Even at the same locality, are more 
complete, in some respect, than any we had previonsly seen ; 
and from these we are satisfied that it is not a vertebral col- 
umn, but really an articulated animal. As it seems impossible 
that it can be a Crustacean, an Annelid, or larval insect, we can 
scarcely doubt that it is a gigantic Myriapod. : 
One of the specimens now before us seems to be entire, and 
has apparently a sub-hemispherical head, as wide as any part 
of the long slender body. It is not in a condition to show the 
eyes, if any existed, nor can we see any remains of mandibles, 
antenne, or other appendages connected with it. The entire 
length of this specimen is 3°90 inches, and its breadth about 
0:20 inch. It tapers very little from the anterior to the poste- 
rior end, which terminates rather abruptly. In the whole 
length, as many as seventy-five or seventy-six segments can b 
counted ; but it is worthy of note, that there are only half this 
number on the dorsal side, where each one corresponds to two 
low.t As seen in a side view, the downward curved ends of 
the dorsal scutes, if we may so call the larger dorsal portions 
of the segments, are rounded in outline ; while each of them 
_* At that time, we had only seen specimens showing the dorsal spines dis- 
ey cred maliarity ea nents of the body ocours in some types of existing 
fi va Cormatide, in which the dorsal scutes are also generally 
Spiniferous. 
