PLATE XVII. 



Sciiizoblastus Sayi, Shumard, sp., p, 22 I . 



l'i 

 Pig. 1. Cross section of an ambulacra] Held and the hydrospirea attached, five tubes on 



eaeli side; the lancet-plate is trebly perforated. SllbcarboniferoUB, Iowa. 



Coll. Wachsmuth. x !• 54 



Sciiizoblastus Rofei, /•;. fif C, p. 228. 

 Fig. 2. A similar section, one hydrospire-tube on each side. Carboniferous Limestone, 



Wexford. x 10 92 



Granatocrinus campanula™ s, McCoy, sp., p. 251. 

 Fig. 3. A similar section, one bydrospirc-tubc on each side. Carboniferous Limestone, 



Lancashire. x 15 92 



Granatocrinus Derbiensis, G. B. Sby., sp., p. 250. 

 Fig. 4. A similar section, one hydrospire-tube on each side, the lancet-plate perforated by 

 a single canal, and one side plate remaining in place. Carboniferous Lime- 

 stone, Lancashire. x 10 46 



Granatocrinus orbicularis, G. B. Sby., sp., p. 248. 

 Fig. 5. A similar section to Fig. 3. Carboniferous Limestone, Lancashire. X . . .92 



Granatocrinus ellipticus, G. B. Sby., sp., p. 253. 

 Fig. 6. A similar section, with the sacs of the hydrospires large and pyriform, and the 



lancet-canal visible. Carboniferous Limestone, Lancashire. x 8 . . . . 46 



Fig. 7. A similar section of a wide ambulacrum, one hydrospire-sac on each side, and 



the lancet-canal visible. Carboniferous Limestone, Lancashire. x 1 1 . . 92 



Granatocrinus Norwoodi, O. *>• S., sp., p. 245. 

 Fig. 8. A similar section, showing the side plates in position, the lancet-canal, and the 

 hydrospire-canals seeming to perforate the radial plates. Subcarbouil'crous, 

 Iowa. x 12 46 



Mesoblastus angulatus, G. B. Sby., sp., p. 185. 

 Fig. 9 A similar section, the side plates in position, the lancet-canal visible, and three 



hydrospire-tubes on each side. Carboniferous Limestone, Lancashire. x (! l(i 



Ml MH5LASTUS elongatus, G. B. Sby., sp., p. 186. 

 Fig. 10. A similar section, with the lancet-canal visible and three hydrospire-tubes on each 



side. Carboniferous Limestone, Lancashire. x 8 'J.'.' 



Plxtkemitidea Paillettei, de Verneuil, sp., p. 172. 

 Fig. 11. A similar section. Eight hydrospire-tubes are present on each side, the 

 uppermost ones almost piercing the substance of the radials ; and the lancet- 

 plate is grooved beneath. Lower Devonian, Asturias. x 6 49 



