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II.—Synopsis of the Genera and Species of Carboniferous Limestone Trilobites

Published online by Cambridge University Press:  01 May 2009

Extract

IV.—Brachymetopus, M‘Coy, 1847.—General form elliptical; head-shield semicircular, and slightly pointed, about one-third wider than long; glabella small, somewhat elevated, one-third the width of the entire shield, and about one-half the length, having a basal lobe on each side, but no short lateral furrows on the glabella; neck-furrow distinctly marked, equal in width to the posterior border of free cheeks; eyes small, smooth, equal to half the length of the glabella; no facial suture visible, only the axal furrow surrounding the glabella and the neck-furrow; free-cheeks slightly convex, nearly twice as long as they are broad, with no visible suture separating them from one another in front of the glabella; margin broad and slightly grooved, angles of cheeks produced posteriorly into spines. The entire surface of the head covered irregularly with a small bead-like ornamentation.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1883

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References

page 536 note 1 M’Coy, Ann. & Mag. Nat. Hist. 1847, vol. xx. p. 230.

page 537 note 1 Report on the Geology of the County of Londonderry, and of parts of Tyrone and Fermanagh (Dnblin, 1843), p. 261.

page 539 note 1 This is not shown in Barrande’s figures of Cheirurus claviger, pl. 40, figs. 1—12, nor in Ch. gibbus, figs. 35—39. but is seen in pi 41, fig. 17; it is also well shown in Triiiucleus ornatus, pi. 29, figs. 1—8, and in Placopaiia Zippei, pl. 29, figs. 30—34; and in Calymene Baylei, pl. 43, fig. 49, and in many others, not referred to by Barrande.