BY R. ETHERIDGE^ JUXR.^ AND JOHN" MITCHELL. 677 



axial groove are clearly visible, also the two rows of tubercles at 

 tlie base of the glabella parallel with the neck-furrow, Bowning. 

 Coll. Mitchall. 



Fig. 4. — Another almost perfecL specimen ; tlie form of the glabella, 

 especially the semielliptical contour of its frontal margin, is dis- 

 tinctly shown. The pygidium of this specimen is about perfect, 

 and distinctly shows the axis of the pleural lobe-divisions. Bown- 

 ing. Coll. Mitchell. 



Fig. 5. — A perfect specimen, slightly enlarged. The lobe-like character 

 of the portions of the free cheeks embracing the front portion of 

 the glabella is well shown, as aie also the natural outline, and the 

 various parts of the animal as viewed from above. Bowning. Coll. 

 Mitchell. 



Encrindkus bowningensis, Foemte. 



Fig.6. — A complete specimen except for tha absence of the free cheeks, 

 exhibiting all the features of the glabella, thorax, and pygidium. 

 Bowning. Coll. Mitchell. 



Fig. 7. — A cephalon with the right fiee cheek in position, and showing the 

 cliatacter of the tuberculation, the deep axial grooves, and the 

 manner in which these traverse the free cheeks. Bowning. Coll. 

 Mitchell. 



Fig.8. — A cephalon and thorax, showing the concentric and quincuncial 

 arrangement of the tuberculation on the glabella. Bowning. Coll. 

 Mitchell. 



Fig. 9. — A cephalon showing the tuberculation of the glabella ver}' dis- 

 tinctly. Bowning. Coll. Mitchell. 



Fig. 10. — A perfect pygidium, which exhibits very clearly all the p3gidial 

 features of the species. Bowning. Coll. Mitchell. 



Fig. 12. — A very fine and mature specimen ( x|^), to show the general out- 

 line and glabella tuberculation. 



Fig. 14. — The same as the above, natural size. Bowning. Coll. Mitchell. 

 [The light line across the figure arises from a crack in the negative 

 from which the print was made], 



Encrinurus silverdai.knsis, E. ds M. 



Fig. 11. — A portion of a cephalon ( xf), showing the character of the tuber- 

 culation and the terminal conical tubercles surmonnting the larger 

 ones, and the fixed cheeks, inconspicuous neck-furrow, but strong 

 neck-annulation, the rounded and tuberculate genal angle. Silver- 

 dale, near Bowning. Coll. Mitchell. 



Encrinurus etheridgki, Mit. 



Fig. 13. — A cephalon without the free cheeks ( x f). It shows the sub- 

 triangular or acutely elliptical contour of the anteiior portion of the 

 glabella, the deep axial grooves, the five pronounced lateral tuber- 

 cles, and the deep spaces between these latter. Yarralumla. Coll. 

 Aust. Museum. 



