222 Mr. F. A. Bather on British Fossil Grinoids : 



Height Widtli below. Width above. 



millim. millim. millim. 



(a) 2.3 8(?) 21(?) 



ib) 23 7-25 23(?) 



(c) 19-75 8 21(?) 



I BB 5, pentagonal, rather wider than high. 



Heio-ht. Width below. Width above. 



millim. millim. millim. 



(a) 6 4-75 7-75 



{b) 5-5 4-2 7 



(e) 5-5 4 6-5 



BB 5, hexagonal; post.B, seen partially in J, heptagonal. 



Height Width below. Width above. 



millim. millim. millim. 



{a) 12 9-5 ll-o 



ih) 10-2 8-5 11 



(c) 10-75 8 10-5 



The measurements of post.B are height 12 millim. in h ; 

 otherwise unknown. 



RE, 5, shield-shaped ; projecting in a slight bulge just 

 below the articular facet, but not curving inwards much 

 towards the radial processes. The facet is smoothly con- 

 cave, with a very slight trace of a ridge ; the axial canal is 

 not separated from the ventral groove by stereom, but, 

 together with it, forms a deep notch. Measurements are: — 



W' idth of 

 Height. Width below. Width above. facet, 



millim. millim. millim. millim. 



(a) .... 8-8 12-25 12 6 



[b) .... 8-5 (?) 10 10-5 ? 

 (c).... 7-2 10-3 10-3 5 



From which it appears that the sides of the radials are almost 

 parallel and that the width of the facet is just half that of 

 the radial. The facet is almost at right angles to the slope 

 of the side and is therefore directed almost upward. 



A portion of anal x is preserved in h. It is about Q'b 

 millim. high and about 5 millim. wide below. 



A portion of rt is also preserved in this specimen. 



A marked concentric ridge surrounds all the cup-plates at 

 a distance of about '75 millim. from the suture. There is 

 also an irregular ornament on the plates, whicli tends to run 

 in concentric circles (PI. XIII. tig, 18), or may have a more 

 radiate arrangement (PI. XIII. tig. 14). 



The characters of the Stem may be inferred from the 

 bottom of the cup, which shows a very large quinquelobate 

 axial canal, shown in PI. XIII. tig. 17, where it has a mean 



