. Catalogues of the Silurian fossils of the island of Anticosti, with descriptions of some new genera and species. Paleontology; Paleontology. 24 CRUSTACEA. Genus Asaphus, Fig. 7. Fig. 7.—Asaphus platyeephalus, from English Head. A. PLATYCEPHALUS, Stokes.—Occurs in numerous localities on the north side and west end of the island. It is not easy to distinguish fragments of this species from such forms as A. canalis, A. megistos, and some others. We have, however, from English Head, a specimen with the head and the first six segments of the body perfectly preserved with the posteri
. Catalogues of the Silurian fossils of the island of Anticosti, with descriptions of some new genera and species. Paleontology; Paleontology. 24 CRUSTACEA. Genus Asaphus, Fig. 7. Fig. 7.—Asaphus platyeephalus, from English Head. A. PLATYCEPHALUS, Stokes.—Occurs in numerous localities on the north side and west end of the island. It is not easy to distinguish fragments of this species from such forms as A. canalis, A. megistos, and some others. We have, however, from English Head, a specimen with the head and the first six segments of the body perfectly preserved with the posterior angles of the cheeks clearly developed. I believe, also, that some detached pygidia from Gamache Bay in Div. 1, A. G., belong to this species. A. NOTANS, n. sp.—Form ovate, broadly rounded at both extremities, pygidium obscurely trilobed, cheeks terminating in small spines. Head strongly convex, semi-elhptical or rather lunate uniformly rounded in front, the margin from a line crossing a little in front of the eye backwards to the points of the spines somewhat straight but sloping outwards. Eyes about one-third the whole length of the head and so situated that a hne drawn across the head at the mid-length would touch their anterior angles. The terminal spines are acutely sub-conical, rounded on the inner side and with, apparently, a sharp edge on the outside ; they extend backwards to about the third pleura. Length of the head from the front to posterior margins in a straight line (or by callipers) a little less than half the width at the posterior margin and also about one-eighth less than the length of the thorax. The latter is distinctly trilobed, the axis moderately and uniformly convex and a little more than one-third the whole width. Pyg- idium moderately and uniformly convex, nearly a semicircle, its length a little more than half its width ; no concave groove round the margin ; the. Please note that these images are extracted from scanned page images that may h
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