Plate VIII. — The internal ca<t. 



Fig. 1. — Actinal surface, showiug peristomial and anal areas clearly, and the 

 subvective grooves here occupying an almost strictly radial position and 

 marked i-v from left posterior to right posterior. 



Fig. 2. — Side view, showing the curvature of the subvective grooves. The anterior 

 groove (iii) passes across the middle of the figure. The plates of the right 

 anterior interradius (between iii and iv) are fairly distinct. 



Fig. 3. — Abactinal surface, showing in its central area a portion of the original 

 test (compare PI. X, Fig. 8). The numbers i-v here correspond to those of 

 Fig. 1, and mark the radii, while the subvective groove corresponding to each 

 number is now seen to have passed through fully one -fifth of the circumference 

 away from it: e.g. the anterior groove (iii of Fig. 1) now comes into the 

 right anterior radius (iv). Close to number ii some matrix fills the groove, 

 and on this is the impression of a columnal of some crinoid or cystid. 



[1900 203] 



