676 SILURIAN TRILOBITES OF NEW SOUTH WALES, V., 



of which, perhaps, the free cheeks of E. hoivningensis afford the 

 most typical examples of this feature. The border of the larger 

 cheek lobe is prominent and tuberculate, but less so on the 

 smaller one; the furrow also is distinct on the larger portion. 

 The palpebral lobe bearing the eye is small and very narrow 

 between the latter and the marginal furrow, also sparsely tuber- 

 culate; the eye, front to back, is relatively long, and occupies 

 practically the whole of the space between the axial furrow 

 anteriorly and the posterior branch of the facial suture ; it is 

 slightly pedunculate and subconical, with the peduncle sur- 

 rounded by a sulcus. 



The vertical shallowness of the lobe which bears the eye and 

 its great relative size place the specimen apart from other Aus- 

 tralian Encrinuri. Found associated with an Odo7itopleura, 

 near 0. rattei, E. & M. 



Loc. and Nor. — Tarlo River, near its head- waters, Parish 

 Turrallo, County Argyle. Upper Silurian(l). 



e. —The imperfect pygidium(Pl.lvii.,fig.7) is moderately tumid, 

 axis moderately arched, twelve annulations are present, but the 

 posterior portion is missing; annulations are apparently con- 

 tinuous. Only six segments of the pleural lobes are present; but 

 when complete would seem to have possessed eight. Regarding 

 it, we can only say definitely that it is the pygidium of an Eiia-i- 

 nnrus, and probably belongs to the same species as does the 

 preceding free-cheek. 



Both the preceding free-cheek and this pygidium are distinct 

 from any we are acquainted with. 



Loc. and Hor. -Tarlo River, Parish Turrallo, County Argyle. 

 (l)Upper Silurian. 



EXPLANATION OF PLATES LIV.-LVIL 



Plate liv. 



Encrinurus MiTCiiKLLi, Foevste. 



Fig. L — All almost entire specimen, with the free cheeks turned outwards; 



slightly enlarged, downing. Coll. Mitchell. 

 j^ig.2. —Another nearly complete specimen. Kowning. Coll. Mitchell. 

 Fig.3. — A cephalon with free cheeks jn position, the left one being imper- 

 fect. On the right side, the eye and the tubercles bordering the 



