PLATE 78. 



Fif* 



Fig. 1-7. LicHAs ptJSTTTLOsrs. 868 



1. A part of the head, showing the median lobe and anterior lateral lobes of the glabella, 

 the occipital furrow and annulation. The specimen has been crushed, and some parts of 

 it are incorrectly represented. 



2 8t 3. Fragments showing the lower side of what appear to have been the movable cheeks. 



4. The pj-gidium, which is nearly entire in all its parts, except the protuberance and the 

 spines .it the extremity of the axis, which are broken off. The short spines towards the 

 jwsterior extremity are, in this specimen, a little on one side of the centre. 



6. A fragment of the pygidium, where the posterior part of the axis is extremely prominent, 

 and the bases of the principal and smaller lateral spines arc preserved. The continuation 

 of the ribs is preserved only in outline. 



6. The underside of a part of the pygidium, showing the thickened border, the sharp eleva- 



tions separating the ribs, and those marking the furrow upon them. The round pits indicate 

 the bases of the large tubular spines, which ornament the surface with some regularity. 



7. The lower side of a pygidium, showing the broad thickened border and the deep cavity 



made by the protuberance at the extremity of the axis. The bifurcations of the central 

 lobe are more diverging than usual, but this feature is accidental in tlie specimen. 



