32 CARBONIFEROUS TRILOBITES. 



specimens do not confirm this), which diminish successively; the lateral lobes have 

 about thirteen costge, simple and united at the margin by a smooth rim, the 

 furrows which divide the costas becoming obsolete or nearly so before they reach 

 the outer edge ; this smooth rim occupies about one third of the breadth of the lobe. 

 " When rolled up this smooth rim partly covers the wings of the thorax. 

 .... It is remarkable that M. de Koninck, in his excellent ' Description des Anim. 

 foss. dans le terr. Carbonif. de Belgique,' though figuring (pi. liii, fig. 1) a 

 Trilobite with strongly reticulated eyes, as P. glohlceps, states in the text, in more 

 than one place and most particularly, that the eyes are smooth. Indeed, although 

 his description is in general accurate enough, his plate represents a fossil, which 

 in many respects totally differs from the Asaphus globiceps of Phillips to which he 

 refers it." 



10. Griffithides aoanthiceps, H. Woodiv , sp. nov. PI. VI, figs. 2, 10, and 11 ; 



and PI. VII, figs. 2 and 3. 



Head-shield semicircular, produced in front, glabella very gibbous, overhang- 

 ing the anterior margin, twice as wide in front as at the nuchal furrow, the whole 

 surface strongly granulated ; basal lobes very small, rounded ; neck-furrow deep ; 

 neck-lobe rounded ; fixed cheeks exceedingly narrow, scarcely discernible, forming 

 a rounded palpebral lobe (the surface of which is granulated) over each eye and 

 a narrow rim around the glabella ; eyes small, finely faceted ; inner raised portion 

 of cheeks granulated, margin smooth, posterior angle produced into long cheek- 

 spines equal to the glabella in length. 



Thorax consisting of nine free segments, surface of thorax smooth without 

 ornamentation ; axis arched, rather wider than its pleurse, broader next the head 

 and diminishing very slowly to the pygidium ; each of the pleurae strongly grooved 

 down the centre, posterior portion rounded and slightly raised, anterior portion 

 slightly depressed ; fulcral points distinctly marked, extremity of pleurae faceted 

 in front and rounded. 



Abdomen or pygidium composed of about thirteen coalesced somites, border 

 smooth, shghtly channelled, ribs terminating close to border. Extremity of 

 pygidium very slightly pointed. 



The specimens in which the head, thorax, and abdomen of this species are 

 preserved united, are figured on PI. VII, figs. 2 and 3, having been discovered too 

 late for insertion on PI. VI. 



Formation. — Carboniferous Limestone. 



Localities. — Craco, near Grassington; Settle, Yorkshire; and Castleton, Derby- 

 shire. 



