Yol. 56.] AND CICEKOCKINUS. 269* 



radials. Prom this intermediate form the normal Pisocrinus-caljx 

 arises by an overgrowth towards the anterior of the left posterior 

 basal, while the calyx of Cicerocrinus is produced by an over- 

 growth of the left anterior basal posteriorly. The radial plates of 

 the calyx of Cicerocrinus correspond in their arrangement precisely 

 with those of Pisocrinus, and differ only by their more elongate 

 form, as is shown in the accompanying diagram (fig. 3), which 

 is drawn to scale. The plate marked x by Mr. Bather is seen 

 in a position precisely corresponding to that which it occupies in 

 Pisocrinus. 



It would thus appear that no essential difference distinguishes 

 the calyces of Cicerocrinus and Pisocrinus ; it is otherwise, how- 

 ever, when we pass to a consideration of the arms. These are five 

 in number, well developed, and by no means excessively slender ; 

 in length they measure 37 mm., and in breadth 2*3 mm. near their 

 origin, and 1*5 mm. near their termination. They are branched,, 

 pinnulate, with alternating syzygial ossicles. 



The primary brachials are two in number, their breadth is 

 2*3 mm., and their length taken together is 4 mm. The secondary 

 brachials number eighteen : the length of the series is 16 mm. and 

 its breadth 2 mm. The tertiary brachials are as many as twenty- 

 eight, the length of the series being 17 mm., and its breadth 1-5 mm. 



The strong pinnules are plainly exposed on one side of the 

 second and third divisions of some of the arms. A single pinnule 

 arises from every fourth ossicle on one side, so that syzygial sutures 

 may be inferred ; occasionally, however, three ossicles intervene 

 between two successive episyzygials. The articular surface for the 

 pinnules is large, and the next ossicle which succeeds the epi- 

 syzygial is deeply excavated to receive the basal joint of the pinnule. 

 The ossicles of the pinnules are few in number, and longer than, 

 broad. 



The structure of the arms agrees closely with that of these 

 organs in Ectenocrinus, as represented diagrammatically by Mr,.. 

 Bather, 1 though the pinnules of Cicerocrinus are represented by 

 armlets in Ectenocrinus. 



The association of branching pinnulate arms with a calyx pos- 

 sessing the characters of Pisocrinus renders necessary the erection 

 of a new genus, for which I propose the name Cicerocrinus. 2 

 The form described is the only known example of the genus, and 

 may be specifically designated elegans. 



The calyx of Cicerocrinus is that of a Pisocrinid ; the arms those 

 of a Heterocrinid : but this conjunction of characters, though ren- 

 dering necessary a fresh definition of the Pisocrinidae, cannot be 

 regarded as breaking down the distinction between this family and 



1 Ann. & Mag. Nat. Hist. ser. 6, vol. v (1890) pi. xv, fig. 7. 



2 Cicer, ciceris, a chick-pea. 



Q. J. G. S. No. 222. tj 



