18 DEVONIAN TRILOBITES. 



Subgenus — Phacops, as above. 

 2. P. (Phacops) granulatus, Munster. PI. I, figs. 1 — 4. 



Calymene, sp., Sow. Geol. Trans., 2nd series, vol. v, pi. 54, figs. 23, 24, 1840. 



— gkanulata, Milnst. Beitr., Heft 5, t. v, fig. 3, 1842. 



— l^vis, Id. lb., t. v, fig. 4. 



— granulata, Phillips. Pal. Foss., fig. 248 (exclude figs, m, n, o,p), 1841. 

 Portlockia granulata, M'Coy. Synopsis Woodw. Foss., p. 177, 1851. 



Not an inch long. General form broad-oval. Head semicircular, very convex, 

 covered with granules, the sides much bent downward. Glabella fully half the width of 

 the head, very tumid, slightly pointed in front and overhanging the front margin. Its 

 greatest width exceeds its length, even including the neck-segment. Sides converging at 

 an angle of 90°, the base narrow ; a small basal lobe, with a tubercle on each side, but 

 no trace of upper furrows. Cheeks moderate, with a strong border. Eyes large, 

 prominent, with few, about thirty-six lenses, five in a row. (M'Coy.) 



Thorax ? — 



Tail semicircular, small, convex, with a smooth, declining, distinct margin, and 

 prominent conical axis, reaching rather more than two thirds down, tapering and almost 

 pointed at the extreme end, which fades into the limb, marked with six or seven rings, 

 obscure at the tip. The lateral lobes have five or six strongly duplicate furrows. 



There seems no good reason for separating Munster's C. lavis from the above. It is 

 merely a decorticated specimen, the surface-granulation consequently absent. The tail, 

 as figured by Munster, has too many ribs, and too long an axis, but is otherwise like 

 ours ; and Munster's figures are not fully to be trusted. 



Locality. — Upper Devonian. Petherwin, Cornwall. (Our best specimen, fig. 1, is 

 from Mr. Pengelly's cabinet ; the others from the Mus. P. Geology.) 



P. (Phacops) latifrons, Bronn. PI. I, figs. 9 — 16. 



Calymene latifrons, and C. Schlotheimii, Bronn., in Leonhard's Zeitscbr. f. d. 



Miner., 317, t. ii, figs. 1—8, 1825. 

 Calymene latifrons, Bronn. Lethaea. Geogn., t. ix, fig. 4, 1835. 



— tuberculata, Murch. Sil. Syst., pi. xiv, fig. 4, 1837. 



— Latreillii, Steininger. Memoires Soc. Geol. France, vol. i, pi. ii, 1834. 



— Schlotheimii, C. Brongniartii. Ibid., p. 350, 351. 



— Latreillii, Phillips. Pal. Foss., fig. 249, 1841. 



— accipitrina. Ibid., p. 128. 



Portlockia latifrons, M'Coy. Synops. Woodw. Mus., 1851, p. 177. 

 Phacops latifrons, Sandberyer. Verstein. Rheiniscb. Schicbten-Syst. Nassau, t. i, 

 fig. 7, 1850. 



— — Roemer. Palseontographica, vol. iii, t. ix, figs. 24, 25, 1854-1855. 



