402 



Dr. P. H. Carnenter on the 



lacrorura subtus visse, assuHs connatis inferioribus brachii 

 maximam partem demtis " *. Zittel, who gives a copy of 



Portion of a free ray of Crotalocriinix jmhher, %eei\ from the dorsal side. 

 The arm-joiuts (interradials, W. & S.) are preserved at the proximal 

 end of tlie specimen ; but tbey have partially fallen away at the 

 distal end, so as to expose the inferior or dorsal surfaces of the 

 ambulacral covering plates. (After Angelin.) 



this very same figure fj is still more explicit in his explana- 

 tion of it : — " Die Armstiicke von der Riickenseite, um die 

 Verbindung derselben zu zeigen ; gegen oben sind die Dorsal- 

 stiicke weggebrochen und nm" die Saumplatten mid die 

 Decktafelchen der Arabulacralrinne von unten zu selien." 



So far then as the free rays of Crotalocnnus are concerned 

 I do not think that Wachsmuth and Springer will again 

 venture to assert that the covering plates were roofed over by 

 a " pliable ventral covering " formed of calyx-interradials ; 

 and much of the following argument from pages 64- and 65 of 

 part iii. is therefore altogether worthless : — 



"This is of some importance as demonstrating that a pliable vault 

 may enclose another flexible integument and contain the food- 

 grooves underneath, which was seriously questioned by Carpenter 

 (Chall. Hep., p. 182). He evidently overlooked Crotalocrhius, 

 for we doubt if he could have taken the small covering plates 

 (Icongr., pi. 17, fig. 3 a) for the representatives of the large rigid 

 plates 4: of figs. 6 and 7 on pi. 6, or the irregular pieces around 

 the oral pole to be summit-plates." 



It seems to me that the charge which Wachsmuth and 

 Springer bring against me of having " evidently overlooked 

 Crotcdocrinus " has treated them like the proverbial chicken 

 and come home to roost. I will again express my belief that 



* In figvu'e IG of tab. xxv., which Angelin described as '^ Brachia con- 

 nata subtus visa," the arm-joints {interradials, W. & S.), which are 

 mostly removed in fig. 15, are seen in their natural position, 



t ' Handbuch der Palfeontologie,' i. Band, p. 357, fig. 244 d. 



\ It would be well if the authors would explain how these " rigid " 

 plates can have formed part of a " pliant vault " which consisted of "■ a 

 continuous integument of plates connected by ligament in place of 

 suture " (p. 65). 



