. The Canadian naturalist and geologist. Natural history -- Periodicals. Trof, Hall on a New Crustacean, 445 thickened border; the posterior angles rounded. The margin is impressed or sinuate in front, and there are slight indications of longitudinal grooves on each side of the central, leaving a median lobe proportionally wider than in Limulus. The eyes, though imperfect, remind one somewhat of the eyes of Trilobites, and are remarkably Carapace of jlglaspis from Wisconsin. There is a single fragment of what appears to have been an ar- ticulation of the thorax, or a portion of som
. The Canadian naturalist and geologist. Natural history -- Periodicals. Trof, Hall on a New Crustacean, 445 thickened border; the posterior angles rounded. The margin is impressed or sinuate in front, and there are slight indications of longitudinal grooves on each side of the central, leaving a median lobe proportionally wider than in Limulus. The eyes, though imperfect, remind one somewhat of the eyes of Trilobites, and are remarkably Carapace of jlglaspis from Wisconsin. There is a single fragment of what appears to have been an ar- ticulation of the thorax, or a portion of some appendage analogous to the branchial feet of Limulus ; it has a flattened, curving, point- ed extremity. Another fragment I infer may have been the cau- dal extremity ; it is comparatively thick and strong; but the spe- cimen is too imperfect to be determined. The first specimen I obtained is a straight spine-like body, and I infer that the animal may have been provided with a caudal spine, as in Limulus. Such, in general, are the characters of this crustacean. Whether this may have been the animal which made the peculiar tracks in the sandstone, I cannot say, but I have so inferred. The first speci- men was found at a distance of thirty miles or more in a north- westerly direction from the locality of the tracks of Black River, and in higher beds of the sandstone. The last found specimens are from a more distant locality, in a southeasterly direction, and also from beds above those of the tracks. All this, however, can- not furnish matter for argument against the origin of the tracks, in the present state of our knowledge of a country which has been comparatively but little exj)lored. Whatever may be proved hereafter in this respect, it does not diminish the great interest attaching to so new and remarkable a form of crustacean from the unequivocal primordial zone of the Please note that these images are extracted from scanned page images that may have been digit
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