TUI.oMTKv 711 



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outward curve following the margin- of tin- frontal glabellar lobe, am! recurving 

 anteriorly, tin- branches of the *utnre meeting at an angle in the median line at, or 

 ju*t within the frontal margin of the cephalon. Met ween the anterior limit* of the 

 suture ami the frontal lobe is a smooth, flat area. 



The glahella is broad and expanded anteriorly, narrowing backwards, it* 

 anterior width being fully twice, that at the occipital ring. Its surface is quite 

 Miiooth ami evenly convex with an olisciire median longitudinal ridge traversing its 

 entire length. The extreme lateral points of the frontal lobe lie about one-fourth 

 the length of the glahella from the anterior margin; thence the lateral outlines 

 converge in nearly straight lines' to points just above the palpebral lobes, where 

 there is a slight inward deflection on each side, which represents the position of the 

 tir*t glabellar furrows. Below this is a pair of more conspicuous depressions, or the 



id lateral furrow-., which begin opposite the middle of the palpebral lobes, pass 

 directly inward for a short distance and then backward, extending quite to the 

 occipital furrow. These furrow* are not deep but the lobes thus cut off are quite 

 distinct. The posterior median portion of the glabella between these furrows is 

 narrow and the low axial ridge tr.ivereing it terminates at the neck ring in a round, 

 blunt elevation. These features, with the exception of the prominence of the basal 

 lobes, are throughout characteristic of the typical Asaphus, and the accompanying 

 figure may be compared with that of Asaphus expansus given on a preceding page. 

 The occipital ring is arched and moderately prominent. 



Flga. 15, 16. Pygldla of Oercuaphei 



I'ygidium multiM-gmented, outline suhparahnlir. margin entire. Surface very 

 convex medially, lateral iortions depressed convex. Horder broad and Mat, being 

 widest at the {Mist-lateral edge?, narrowest at the anterior angles and posterior 

 extremity. At the latter point then i> a slight incurvature of the margin. The 

 outline of the convex portion of the shield i* Mihtriangular and quite diUerent from 

 that of the margin. 



Axis quite narrow, highly convex, longitudinally arched and extending to the 

 marginal border. It bear< In 11 distinct aiinulation*. the anterior ones being 

 separated by broad grooves. Only the posterior extremity i* unsegmented. 



The pleura- bear 7 ribs on earh >id.-; these are narrow, straight, transverse. 

 slightly reflected except at their outer extremities on the margin. Kach of these 

 sharply defined ribs is divided by a deep sulcus broader than the interannular 



