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



Anal x or Brachianal somewhat rounded and protuberant J 

 height 3'5 millim., greatest width 4 millim. It supports three 

 plates, of which the middle one is 2*1 millim. high and 3*1 

 millim. wide. 



Of the Ventral Sac only the 11 proximal millimetres are 

 exposed ; the width here is 7 millim. The plates are flat, 

 not ridged, and wide, with well-marked lateral folds. 



The Stem : — only 5 proximal ossicles are preserved ; these 

 make together a length of 1*5 millim., and have a diameter 

 of 3 millim. The ossicles alternate in size; the section or 

 the larger ones is pentagonal, that of the smaller ones quin- 

 quelobate. The sutures are crenelated, but the strias seem 

 restricted to the edge, the inner part of the lobes being smooth, 

 somewhat as in Pentacrinus. The stem is not clearly repre- 

 sented in the figure. 



The radial sutures are very clearly seen in section, though 

 not externally. The lumen is pentagonal, with a diameter 

 of *75 millim. 



The abnormalities in the branching of the arms are as 

 follows : — The left posterior ray has the fourth costal axil- 

 lary : following first the left branch, we see clearly two 

 distichals, of which the second appears to be axillary ; the 

 outer branch from this distichal must, however, have been 

 small, probably merely an armlet, possibly only a rather stout 

 pinnule; the inner branch from this distichal is a normal 

 main arm with pinnules : now taking the right branch we 

 notice one distichal, and this is axillary giving rise to two 

 main arms with pinnules ; in each of these main arms the 

 first pinnule is given off on the outer side of the second 

 ossicle, and in the right of these two main arms the first 

 pinnule seems to have been stouter than those succeeding. 

 The right posterior ray has unfortunately lost all its costals 

 and some of the succeeding ossicles ; we shall, however, 

 probably be right in referring to this ray the two main arms 

 that lie in the middle of the specimen : the left main arm, 

 however, appears to bifurcate on an early ossicle, the first 

 preserved, and the outer branch, at first hidden, emerges from 

 under the other arms about halfway up the specimen ; such 

 at least is my interpretation ; the other branch of the left 

 main arm continues regularly up to the ninth ossicle of those 

 preserved ; this ossicle is shaped like an axillary and probably 

 gave rise to a fairly stout armlet or pinnule, which, however, 

 is hidden from view ; the eleventh ossicle likewise gives off a 

 stout pinnule, on the other side, after which the arm is 

 normal. It seems possible that there was some accident to 

 the arm at the ninth and eleventh ossicles just mentioned, and 



