156 



ECHINODERMATA— PELMATOZOA 



PHYLÜM IV 



Proteocystites Barrande. Lower Devonian ; Bohemia. Carpocystis Q^hlert. 

 Lower Devonian ; France. 



Family 2. Glyptosphaeridae Bather. 



Food-grooves extend over the calyx well heyond the adoral ärclet, arid irregularly 

 transgress the sutures between the plates. Diplopores diffuse. 



Glyptosphaerites Müll. (Fig. 228). DifFers from Sphaeronites in having 

 long, branching, ambulacral grooves, and a short, well-developed stem. Arms 

 recumbent and grooves beset with small plates. Ordovician ; Eussia and 

 Sweden. 



Fungocystiies Barrande. Clavate. Ordovician ; Bohemia. 



Family 3. Protocrinidae Bather. 



Food-grooves extend over the calyx almost to the adoral pole, and are regularhj 

 hordered hy alternating plates on which are the brachiole-facets. Diplopores diffuse, 

 or confined to the adamhulacrals. 



Frotocrinites Eichw. (Fig. 246). Nearly hemispherical, non-pedunculate. 

 Ambulacral grooves long and branching ; arms un- 

 known. Ordovician ; Russia and Bohemia. 



Proteroblastus Jaekel (Dadylocystis) (Fig. 247). 

 Ordovician ; Russia. 



Fig. 246. 



Protocrinites oviformis Bichwald. Ordovician ; Pulkowa, Russia. 

 a, Calyx viewed from above ; h, Same from below showing basal 

 plate in the centre (affcer Volborth), 



Fig. 247. 

 Froterohlastus schmidti Jaekel. 

 Ordovician ; Esthonia ; anih, food- 

 grooves ; hr, brachioles ; iamh, 

 inter-ambulacrals ; o, mouth (after 

 Jaekel). 



Mesocystis Bather (Mesites Hoflfmann ; Agelacrinus Schmidt). Ordovician ; 

 Russia. 



Family 4. Gomphocystidae Bather. 



Amhuloxra in five main grooves curving around the calyx, and not prolonged to 

 the brachioles. 



Gomphocystites Hall. Calyx flattened above, greatly elongate below, com- 

 posed of many irregulär plates, pierced by diplopores. Covering plates often 

 developed, and grooves sunk below the thecal surface. Silurian ; North 

 America and Gotland. 



Pyrocystites Barrande. Ordovician ; Bohemia. 



