CTENOPYGE BISULCATA. 81 



Dimensions. — Oranidium 2*8 mm. long, 4*0 mm. wide at the eyes, <>■;> mm. at the 

 posterior margin ; thorax (probably incomplete) L"2 mm. long, 5'8 nun. wide. 



In the form of its glabella this species is not unlike Sphdsrophthalmus alatus, 

 and it shows a still more striking resemblance to the cranidinm figured by 

 Linnarsson as Sph. maj us cuius ; but from both of these species it is distinguished 

 by the wide expansion of the fixed cheeks behind the eyes and by the absence of 

 the strongly marked continuous glabellar furrows. 



Of the species of Gtenopyge it resembles most closely Gt. bisulcata and Gt. 

 falcifera. In both of these the axis of the thorax is about equal to the pleurae in 

 width, as in the present species; but in them it is straight-sided, while in Gt. 

 fusiformis it is fusiform. Moreover, in Gt. bisulcata and Gt. falcifera the pleura3 

 are produced into long spines, in Gt. fusiformis they seem to end in short points — 

 it is, however, possible that these may be longer than they appear in the specimen. 

 In the emarginate front of the cranidium the present species differs from Gt. 

 bisulcata and Gt. falcifera and resembles Gt. pecten and Gt. teretifrous, but it differs 

 from them all in the shape of the glabella and the character of the glabellar 

 furrows. Excluding the neck-fnrrow there are no definite furrows of any kind 

 upon the glabella, but this no doubt is due in part to imperfect preservation. It 

 does not appear possible, however, that the furrows can ever have been strongly 

 marked or that they were continuous across the glabella. 



Horizon and Locality. — Upper Lingula Flags : Malvern. 



2. Ctenopyge bisulcata (Phillips). Plate VIII, figs. 15— 19 ; Plate IX, figs. 1—4. 



1848. Olerms bisulcatus (pars), Phillips, Mem. G-eol. Surv., vol. ii, pt. i, p. 55, fig. 1, p. 346 ; not 



fig. 2. 

 1864. Olenus bisulcatus (pars), Salter, Mem. Geol. Surv., Brit. Org. Remains, dec. xi, pt. viii, p. 8; 



not pi. viii, fig. 6. 

 1866. ? Olenus (Sphivrojjhthalmus) alatus, Salter, Mem. Geol. Surv., vol. hi, p. 302, pi. iv, fig. 3. 

 1871. Olenus bisulcatus , Phillips, Geology of Oxford, p. 68, fig. 7. 

 1871. ? Olenus pauper, Phillips, op. cit., p. 68, fig. 4. 

 1880. Ctenopyge bisulcata, Linuarsson, Geol. Foren. Stockh. F6rh., vol. v, p. 153, pi. v, figs. 18, 19, 



pi. vi, figs. 1, 2. 



Head wide, weakly emarginate in front, with long curved spines springing from 

 the sides of the cheeks. Glabella rather convex, almost parallel-sided, rounded in 

 front. The anterior glabellar furrows obsolete, the posterior pair well marked, 

 meeting across the glabella but rather shallower towards the middle line ; neck- 

 furrow strong, but also shallower in the middle than at the sides, neck-segment 

 with a median tubercle. Eyes large, placed a little behind the middle of the cheeks 

 at a distance from the glabella about equal to two-thirds the width of the latter, 

 ocular ridge oblique. Facial suture cutting the anterior margin a little to one side 



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