28 CARBONIFEROUS TRILOBITES. 



cularly A. expansus and Hemicrypturus BazamoivsJcii of Green ; but .... there is 

 a perfectly developed pygidium, closely resembling that of Pliillipsia. From the 

 abundance of such pygidial rehcs, and the total absence of any other, it may fairly 

 be presumed that a pygidium with axal and lateral segments fully developed was a 

 generic peculiarity. The glabella is also more elevated than in the true Asaphs. 

 In the absence of perfect specimens the formation of a new genus is difficult; but since 

 the group is distinguished from the Asaphs of older rocks by the fully developed 

 pygidium, it is advisable to separate them. It may also be here remarked that 

 Green's cast of Hemicrypturus BazamowsJciif and Pander's figures of A. expansus, 

 seems to show that the lateral segments of the thorax in those species were com- 

 pound, as in Phacops and Calymene, whereas they are merely folded in Asaphus 

 latifrons of this work ; in the species here figured they are also compound, so that 

 there appears to be a blending of the characters of the several sections one into the 

 other." 



8. Griffithides seminifeeus, Phillips^ sp. 1836. PI. Y, figs. 1 — 9 ; and PI. VIII, 



fig. 14. 



Asaphus seminifeeus, Phillips. Greol. Torks., vol. ii, p. 240, pi. xxii, figs. 8, 9, 10, 



1836. 

 Phillipsia gemmulifeea, De Koninck. Animaux Toss. Terr. Carb. Belgique, 



p. 603, pi. liii, fig. 3 (noa Phillips), 

 1842. 



— — M'Coy. Synopsis Carb. Foss. Ireland, p. 162, 1844. 



— SEMINIFEEA, Morris. Cat. Brit. Poss., p. 114, 1854 



— — Salter Sf H. Woodw. Cat. and Chart Poss. Crust., p. 15, 



fig. 110, 1865. 



— — R. Woodw. Cat. Brit. Poss. Crust., p. 55, 1877. 



General form ovate-oblong : head-shield arcuate, glabella large gibbous, over- 

 hanging the anterior border ; basal lobe pyriform ; neck-lobe broad, separated by 

 a wide furrow above and below ; eyes small, renif orm, smooth ; raised portion of 

 free cheek, glabella, and neck-furrow coarsely and irregularly granulated, margin of 

 free cheeks smooth, lateral angles not produced into cheek-spines, thoracic seg- 

 ments nine, axis wider than pleurge, only diminishing very shghtly towards the 

 pygidium ; each segment ornamented by a single row of coarse granules (about 

 eight on each side and ten on the axis) ; axal furrows strongly marked ; segments 

 arched, ends of pleuras rounded, faceted portion smooth : pygidium composed of 

 twelve coalesced somites, axis tapering gradually to an obtuse extremity ; side ribs 

 about nine, ornamented each by a single row of tubercles eight to ten on axis, 

 about eight on each pleura ; margin of pygidium narrow, edge bevelled. 



