263 



PROF. W. J. SOLLAS OX BRAHMA CR1NTJS [May I9OO, 



sole important difference between this calyx and that of Pisocrinus ; 

 in the latter, the second of the two plates exclusively united to a 

 radial is the left anterior basal, which meets the middle of the base 

 of the anterior radial. This is correctly indicated both by Bather 



and Wachsmuth 

 Fig. 3. — Analytical representation of the calyx 

 of Cicerocrinus elegans. ( x 2.) 





[The plates of the lowest series are basals, those of the 

 two series of the next zone, radials ; the remaining 

 plates are brachials, except x, which is the anal 

 plate, r— right ; /=left ; a = anterior ; p— pos- 

 terior ; r'=radi-anal.] 



Fig. 4. — Pisocrinus, sp. : an exceptional speci- 

 men, in which the basal plates are sym- 

 metrically arranged, seen from the base. 



RA 



-ArrtARadio® 



& Springer, but, 

 though true for the 

 great majority of 

 examples of Piso- 

 crinus, the relation 

 is not absolutely 

 constant. Out of 

 some hundreds of 

 specimens of Piso- 

 crinus pillula I 

 have succeeded 

 in finding three 

 wherein the ar- 

 rangement of the 

 basal plates is pre- 

 cisely that which 

 obtains in Cicero- 

 crinus, while in a 

 single example the 

 basal plates are 

 disposed in a man- 

 ner almost pre- 

 cisely intermediate 

 to that of Piso- 

 crinus and Cicero- 

 crinus. Thus, as 

 shown in tig. 4, the 

 right posterior is, 

 as in both genera, 

 interradial in posi- 

 tion, and it never 

 exhibits any tend- 

 ency to deviate 

 from this position ; 

 the left anterior 

 and left posterior 

 basals, however, 

 are of approxi- 

 mately equal size, 

 and meet in a lon- 

 gitudinal suture 

 which corresponds 

 to the suture be- 

 tween the anterior 

 and left posterior 



