Reviews — Wachsmufh 8f Springer^s Monograph on Crinoids. 35 



contact with cup-plates are four in number : a plate {x) resting on 

 the truncate upper margin of the posterior basal ; a plate (EA) 

 resting between the posterior and right posterior basals, abutting 

 against x on the left and the right posterior radial on the right, and 



Fig. 11. — locrinus subcrassiis. 

 (Outline after W. & Sp.) 



Fig. 12. — Dendrocritms 

 longidactylus. 

 (After J. Hall.) 



Fig. 13. — Bendrocrinus 



Casei. (Diagrammatized 



from W. & Sp.) 



Fig. 14. — Poteriocrhms Fig. 15. — Cyathocriniis Fig. 16. — Parisocrinus. 



[Scaphiocrinus) elegans. longimanus, anal area. (From MS. drawing lent me 



(After "W. & Sp.) (Diagrammatized from by Wachsmuth.) 

 Angelin by "W. & Sp.) 



supporting by its upper margin a tube-plate ; this latter {rt) rests 

 between x and r. post. R, and is followed by a vertical series of 

 similar plates ; on the left of x, and resting on 1. post. R, is a rather 

 smaller tube-plate {It), also supporting a Yertical series ; x itself 

 supports a median vertical series, of which the proximal plate may 

 be distinguished as mt. 



As to the homologies of these plates, all ai'e now agreed that 

 RA represents the right posterior inferradial, and my name for it, 

 * radianal,' has won general adoption. Tiiis plate, as Wachsmuth 

 and Springer rightly insist, is always found to alternate with the 

 underlying basals ; in the early stages of phylogeny it supported 

 a STiperradial of equal width, but that became squeezed to the right 

 as the anal plates developed : compare Heterocrinus (Fig. o) and 



