PHILLIPS I A. '21 



4. Phillipsia truncatula, Pliil, sp. 1836. PI. Ill, figs. 9—14. 



AsAPHtJS TEUNCATULTjs, Phillips. Geol. Torka., vol. ii, pi. xxii, figs. 12, 13, 183G. 

 Phillipsia obnata, Portlock. Rep. Geol. Loud., p. 307, pi. xi, fig. 2 a, 1843. 

 — TBUNCATULA, M'Coxj. SjD. Carb. Foss. Ireland, p. 163, 1844. 



Eead-sliield broadly arched ; glabella twice as long as broad, rounded in front, 

 only slightly elevated; basal lobes rather produced, with three short lateral 

 furrows on each side, two of which are anterior to the compound eyes ; neck-lobe 

 distinctly marked, and, like the surface of the glabella, rather closely granulated ; 

 fixed cheek narrow behind, forming a small, rounded, palpebral lobe above each 

 eye, and expanding into a wide flat circular border in front of the glabella ; eyes 

 reniform, smooth; raised portion of the free cheek sparsely granulated; border 

 smooth and broad, terminating in a strong short cheek-spine which is striated 

 beneath. 



Thoracic rings wanting. 



Pygidium. — Axis composed of eighteen coalesced somites, with six granulations 

 on each axal segment ; coalesced ribs of border also granulated ; no distinct border 

 to pygidium. 



Formation, — Carboniferous Limestone. 



Localities. — BoUand and Settle, Yorkshire; Castleton, Derbyshire; Monaster; 

 Millicent ; Limerick ; Hook Head, and Malakeede, near Dublin, Ireland. 



This species has happily escaped the fate of its predecessor, having only been 

 named twice, by Phillips in 1836, and by Portlock in 1843. The head has one 

 more lateral furrow than the other species of Phillipsia, and it has the greatest 

 number of coalesced segments in its pygidium of any Carboniferous form. Its 

 nearest ally is Ph. gemmuUfera, figured on the same plate (PL III). 



The following is Prof. Phillips' original description of Phillipsia truncatula 

 given in his ' Greology of Yorkshire' (1836, vol. ii, p. 240). 



" Depressed, mesial lobe of the head quadrisulcate, bituberculate ; the eyes 

 lunate ; limb continuous, truncate, with undulating parallel strias ; six lines of 

 elevated puncta on the abdominal lobe." 



Portlock says^ of this species, which he calls ornata : 



" This specimen is imperfect ; the form of the glabella approximates closely 

 to that of the preceding species [P. Kellii'] ; it does not, however, extend, as 

 in it, to the points of the cheeks or posterior edge of the margin, and its furrows 

 are more strongly marked. The furrows are ornamented by tubercles, and the 

 whole surface is granular. The tubercles of the pygidium are more elevated, but 

 its general form is nearly the same as that of P. Kellii, and it closely resembles 

 Asaphus truncatulus.'^ 



1 ' Geology of Londonderry ' (1843), p. 307. 



