mm species of eossils* 209 



.MiT. XVII. — Description of a new species of Phillipsia, from 

 the lower Carboniferous rocks of Nova Scoiiaj by E, Billings 



JtCGLS., 



'Phillipsia Howl (N. sp.) 



IP, 'Howl Pygidium, The tubercles on the side lobes were orer» 

 looked in the drawing, the specimen being nearly smooth. 



Description. — Pygidium semi-elliptical, strongly convex, width 

 ■&t the anterior margin a -little less than thre ength, seventeen or 

 •^eighteen articulations ia the axis, side lobes with ten or twelve 

 ribs and a smooth border. The axis is very prominent, about 

 one-third the width, gradually and uniformly tapering and ter- 

 minating abruptly at five-sixths of the whole length in an obtuse- 

 ly rounded apex. The ribs on the axis are depressed convex, 

 becoming smaller and more crowded towards the apex, each with 

 ■eight or nine small tubercles, which are confined to the middle 

 ithird of the width of the axis, and are situated near the posterior 

 margin of tfee ribs. The side lobes have ten or twelve depressed 

 convex ribs, the last three indistinct, the first three or four with a 

 very obscure fine groove near the posterior edgQ, in the outer 

 third of the length. The smooth border is about one-fourth the 

 width of the side lobes at the anterior angles, but a little wider 

 t>ehiud ; all the space behind the apex of the axis is smooth. 

 Each rib has nine or ten small tubercles near its posterior margin. 

 On the posterior third of the pygidium there is an obscure shal- 

 low groove along the inner edge of the smooth border. 



Length of the specimen six lines; width at the anterior margia F 

 siearly the same, about one-sixth of a line less. 



This species resembles P. Meramecensis (Shumard), but has a 

 greater number of ribs in the axis of the pygidium. 



P. insigens (Winchell) is a very closely allied species. The 

 pygidium is thus described by Prof. Winchell in the Proc. Acad. 

 Nat. Sci., Phi. January 1863, p. 24. 



" Pygidium very convex, semi-elliptic, the axis very prominent and 



forming about one third the width at the anterior margin ; consisting of 



twelve to fourteen rings each bearing six small tubercles, the whole of 



which are arranged in six longitudinal rows ; the tubercles often worn 



Can. Nat. 14 Vol. VTT 



