F. R. Cowper Reed — JJndescrihed Tnlohites. 307 



surface of the pleiu-a bears no furrow or ridge, but close to the 

 posterior margin are two equal raised thread-like lines parallel to 

 the margin and to each other and separated by a narrow groove. 



The axis of the thorax is very narrow relatively to the pleurae ; 

 it is cylindrical as in Ctenopyge pecten (Salter), not tapering at all 

 posteriorly, so far as is seen in the smaller specimen. In the larger 

 specimen the axis ia too imperfectly preserved to make out any 

 feature clearly. The pygidium, according to the latter specimen, 

 appears to be broadly parabolic and slightly pointed or apiculate 

 posteriorly, but this appearance may be due to distortion and crushing. 

 Its lateral lobes are flat and marked by straight pleura3 similar to 

 those of the thorax, and like them distinctly furnished with the ridge 

 and thread-like lines. They terminate on the margin in free ends, 

 bluntly pointed and back wardly directed, of which six or seven are 

 distinguishable. The axis of the pygidium is not preserved. 



It is extremely doubtful to what subgenus or even genus this 

 imperfect fossil should be ascribed. It however seems more allied 

 to SJtirycare or Ctenopyge than to Splmrophthalmus. The long, 

 straight spinose pleurte of the thorax, the narrow axis, the numerous 

 segments of the pygidium, with the free pointed terminations of the 

 pleuree on its margin, resemble Ctenopyge, but the shorter length of 

 these spines and their falcate shape distinguish them. It is not, 

 however, possible to fix with certainty the true generic position of 

 this imperfectly known species. 



The specimens (a, 275 of Salter's Catalogue) were found in the 

 Upper Lingula Flags of Moel Gron. 



mm. 

 Length of pygidium of larger specimen ... 12-0 



Width of ditto 23-0 



Width of thorax 25-0 



Width of axis of thorax ... ... ... 4'0 



N.B. These measurements are only approximate, owing to the 

 bad state of preservation of the specimen, and its distortion. 



Neseuretus recurvatus (Hicks) ? (PI. XII, Fig. 4.) 



1873. Cali/mene ve.vata, Salter : Cat. Camh. Sil. Foss. Woodw. Mus., p. 22 (a 469). 

 1888. Calymenc vexata, Etheridge : Pal. Foss. Brit. IsL, p. 46. 

 1891. Neseuretus, sp., Woods : Cat. Type Foss. Woodw. Mus., p. 148. 



The small pygidium named by Salter Calymene vexata occurs on 

 a slab with Niobe [_Asap]iellus, Brogger] menapiensis, Neseuretus 

 quadratiis, Ctenodonta menapiensis, and Ctenodonta camhriensis from 

 the Tremadoc Beds (=Arenig, according to Salter) of Ramsey Island. 

 The species is somewhat doubtful, but the pygidium appears to 

 resemble that of Neseuretus recurvatus (Hicks). ^ 



Neseuretus quadratus (Hicks) ? (PI. XII, Fig. 5.) 



1873. Cahjmcne ultima, Salter : Cat. Camb. Sil. Foss. Woodw. Mus., p. 22 (« 469). 

 1888. Calymene ultima, Etheridge : Pal. Foss. Brit. IsL, p. 46. 

 1891. Uali/mcne ultima, V^oods: Cat. Type Foss. Woodw. Mus., p. 141. (Specimeu 

 supposed to be lost.) 

 The slab of rock on which Salter's Calymene vexata occurs also 

 contains his original specimen of Calymene idtima. It consists of 

 » Hicks: Q.J.G.S., vol. xxix (1872), p. 45, pi. iii, figs. 5, 6. 



