54 CARBONIFEROUS TRTLOBITES. 



25. Beachymetopus discobs, M'Coy, sp., 1844. PI. VIII, fig. 15. 



Puillipsta (?) discobs, MCoy. Synop. Carb. Foss. Irel., p. 161, t. 4, fig. 7, 



1844. 

 Bbaohymetopus discoes, M'Coy. Ann. and Mag. Nat. Hist., vol. xx, p. 230, 1847. 

 — Morris. Cat. Brit. Foss , p. 101, 1854. 



Salter Sf H. Woodw. Cat. and Chart Foss. Crust., p. 16, 



fig. 120, 1865. 

 H. Woodw. Cat. Brit. Foss. Crust., p. 27, 1877. 

 — — H. Woodw. Geol. Mag., Decade ii, vol. x. p. 536, 1883. 



This species is founded on a pygidium only, and was in the first instance 

 (1844) referred by M'Coy to Phillvpsia, with a note of interrogation. Later 

 on, namely, in 1847, M'Coy proposed that this species should be placed under 

 his genus Brachymetopus. We have no further information to give concerning 

 B. dtscors, and the only additional specimen we have seen is from the Carboniferous 

 Limestone of Little Island, Cork, and consists of an equally small pygidium to 

 that described by M'Coy, and was obtained by Joseph Wright, Esq., F.G.S., of 

 Belfast, to whom we are indebted for the opportunity of figuring the same. 



The specimen is very obscure and not well preserved. 



The following is Prof. M'Coy's original description of Phillipsia (?) (now 

 Brachymetopus) discors : 



" Specific Characters. — Pygidium semielliptical ; axal lobe reaching to the 

 margin, one third less in width than the lateral lobes, very convex, composed of 

 seventeen narrow segments, the third and fourth unite in the middle of the lobe 

 to form one large tubercle, and towards the apex there are four or five small 

 tubercles, irregularly disposed ; the lateral lobes have only six large rounded 

 segments, each terminating at the margin in a large rounded tubercle, and 

 having usually between the margin and the axal lobe two other large, obtuse 

 tubercles, one of these, on the third and last, being largest, and probably 

 spiniferous ; besides these there are a few irregular granules, especially towards 

 the apex; all the lateral segments seem forked from nearly their origin." 



Prof. M'Coy adds, " I have included this very remarkable Trilobite in the genus 

 Phillipsia, Portlock, although I think there can be little doubt, if better known, it 

 would form a genus distinct from any of those already constituted ; I have named 

 it from the great difference in number of the segments of the axal and lateral lobes 

 of the pygidium. Length of pygidium three lines, width four and a half lines ; 

 width of axal lobe one line." 



Formation. — Carboniferous Limestone. 



Localities. — Millicent Clane, Kildare ; Little Island, Cork. 



