The Canadian journal of industry, science and art . es of this (in a moreor less fragmentary state) are common. Whenperfect, the corners of the head-shield termi-nate in horns, and a spine projects backwardsfrom the base of the glabella. Average lengthone to two inches. ^^s-139. Asaphus.—Head, thorax, and pygidium, of about equal smooth or slightly furrowed, and not much raised. Eyestolerably near together. Hypostoma forked. Body-rings, eight innumber. Our two most common species comprise A. platycephalus,formerly called Isoteles gigas (fig. 140), with rounded head anglesand near
The Canadian journal of industry, science and art . es of this (in a moreor less fragmentary state) are common. Whenperfect, the corners of the head-shield termi-nate in horns, and a spine projects backwardsfrom the base of the glabella. Average lengthone to two inches. ^^s-139. Asaphus.—Head, thorax, and pygidium, of about equal smooth or slightly furrowed, and not much raised. Eyestolerably near together. Hypostoma forked. Body-rings, eight innumber. Our two most common species comprise A. platycephalus,formerly called Isoteles gigas (fig. 140), with rounded head anglesand nearly smooth pygidium, chiefly from the Trenton Group ; andA, Canadensis (Fig. 141), with head-angles terminating in points,and with furrowed pygidium, from the Utica Slate deposits. Frag-ments of this latter form, and sometimes entire specimens, occur ingreat abundance at Collingwood and at Whitby .(see Canadian JournalVol. III., p. 230). The forked hypostoma is shewn at a in the abovefigures. Another species, A. megistos, with smooth pygidium and. MINERALS AND GEOLOGY OF CANADA. 29 horned head-shield, is also common in the Trenton Limestone ofCobourg, The genus asaphus, both on this Continent and in
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Keywords: ., bookcentury1800, bookdecade1850, bookpublishertoron, bookyear1856
