404 Dr. F. A. Bather on British Fossil Crinoids : 



where the indents of one margin alternate with those of the 

 other. This produces a granulate effect. 



The Cirrus-facet is at the margin of the epizvgal and 

 facing downwards, as in B. didactylus, but does not project 

 so far beyond tlie general outline of the columnal. In 

 57543 c (Fig. 7) the outline is elliptical, with the axial canal 

 and fulcral ridges dividing it into unequal halves, the larger 

 being on the outside. The fulcral ridge is straight, on a 

 line with the periphery of the columnal. It thickens 

 slightly round the canal and towards the ends. The floor 

 of the facet is curved as in B. didactylus, but to a less extent. 

 T!ie diameters are l'2xlO mm. on one facet, and 10 x 

 0*9 mm. on the other. Although the inner half of the facet 

 lias not the triangular shape seen in B. didactylus (Baily's 

 drawing being inexact on this), there is an inward pro- 

 longation of its margins which produces an angular outline 

 as seen from the syzygial face and indicates how the 

 excavation might be extended. Other specimens present 

 slight variations of measurement, but the plan is essentially 

 the same. 



The notch on the hypozygal is not so marked as in 

 B. didactylus. 



Cirrals are occasionally preserved, either attached to the 

 cpizygal or lying in a very shallow channel on one or more 

 of the subjacent coluninals. They indicate a rapidly tapering 

 cirrus, of subelliptical section, with the upper (?. e., outer) 

 side flattened, in the way that appeared probable in B. di- 

 dactylus. The greatest length indicated is 9'6 mm. 

 (57543 fi?). 



The number of cirri to a whorl varies between 1, as seen 

 in 57543 d, E 21926, E, 21927, E 5887 a : 2, as in 38620, 

 49834 6, 57540 (lectotype), 57541, 57543 b, c, E 5887 a, b, 

 E 6480, E 21920, E 21929, E 21931, E 21932, E 21934, 

 E 21937, E 5888 (P. sowerbii) ; and 3, as in 49334 a, 

 57541, 57542 a, 57543 a. Fragments containing two whorls 

 are 57541 with 3 & 2 facets, 57543 b and E 5888 with 2 & 2, 

 58887 a with 2 & 1. The an-angement in all of these is 

 as in B. didactylus. The only exception is presented by 

 E 21942, from Harwich, which contains 2 syzygies, one of 

 which appears to bear only 1 facet, and the other 2 facets, 

 separated as usual by a blank radius ; but one of these 

 latter lies on the same radius as the single facet on the 

 other whorl. The specimen, which lies on matrix, has, how- 

 ever, been broken across in several places, and tlie fragments 

 may well have been replaced with the wrong orientation. 



