400 Dr. P. II. Carpenter on the 



ever, contains distinct summit-plates belonging to the actinal 

 system. 3. Therefore it is an " inner integument," and was 

 in reality covered by a " flexible vault" composed of irregu- 

 larly disposed plates belonging to the interradial portion of 

 the calyx or abactinal system, such as form the external 

 covering or vault of Grotalocrinus pulcher and Enallocrinus 

 scriptus. 



The logic of this argument does not appear to me to be so 

 sound that Messrs. Wachsmuth and Springer are entitled to 

 say of their conclusion that they " know it to be true." It 

 will be quite time enough to say this when they have dis- 

 covered either the " inner integument " in Grotalocrinus 

 jpulcher or in Enallocrinus scriptus, or the '^ flexible vault " 

 above this integument in Grotalocrinus rugosus ; but from my 

 own observation of two specimens of this latter type, both of 

 them better preserved than that figured by Angelin, I feel 

 myself entitled to say without fear of contradiction that the 

 central plate and proximals were never covered up by such a 

 " flexible vault " as that of which the existence is '' known 

 to be true " by Messrs. Wachsmuth and Springer. 



For the sake of brevity I pass over their references to the 

 absence of ambulacra in the summit of Grotalocrinus pulcher 

 and Enallocrinus scrijHus, as figured by Angelin, and to the 

 opinions of Zittel respecting the oral plates of Grotalocrinus — 

 both of them points which are open to a considerable amount 

 of discussion — and I will pass on to the other evidence which 

 the American authors adduce in favour of their theory that the 

 central summit-plate and proximals of Grotalocrinus, together 

 with " the entire ventral surface " *, were covered by calyx- 

 interradials extending upwards from the abactinal side, where, 

 by the way, " only occasionally the first interradial is visible 



dovsally"t. 



At the conclusion of the long paragraph quoted above, 

 tab. vii. fig. 6 and tab. xxv. fig. 15 of Augelin's work are 

 referred to in illustration of this theory ; but fig. 6 on tab. vii. 

 simply represents a side view of the calyx of Grotalocrinus 

 pulcher, and I strongly suspect that the authors meant to quote 

 fig. 6 on tab. viii., the summit view of this species to which I 

 have just referred. They continue on p. 64 of part iii, : — 



"The vault of the Crotalocrinida3 extends quite a distance into 

 the free rays, as shown by Miiller's and Augelin's figures (Icongr,, 

 pi. 6, figs. 6 and 7, also pi. 25, figs. 15 and 2q, and Akademie 

 der Wissenschaften, 1853, pi. 13, fig. 10). That those plates are 

 not ambulacral pieces is proved by the fact that they cover the 

 Saumi)latten, and have a different style of ornamentation. Those 



* ' llevisiou,' part iii. pp. 57 and 143. t Ihid. p. 140. 



