156 



ECHINODERMATA— PELMATOZOA 



PHYLUM IV 



ProteoGijstites Barrande. Lower Devonian ; Bohemia. Carpocydis CEhlert. 

 Lower Devonian ; France. 



Family 2. Glyptosphaeridae Bather. 



Food-grooves extend over the calyx loell beyond the adoral circlet, and irregularly 

 transgress the sutures between the plates. Diplopores diffuse. 



Glyptosphaerites Miill. (Fig. 228). Differs from Sphaeronites in having 

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

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

 Sweden. 



Fungocystiies Barrande. Clavate. Ordovician ; Bohemia. 



Family 3. Protocrinidae Bather. 



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

 bordered by alternating plates on which are the brachiole-facets. Diplopores diffuse, 

 or conff,ned to the adambulacrals. 



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

 Ambulacral grooves long and branching ; arms un- 

 known. Ordovician ; Russia and Bohemia. 



Proteroblastus Jaekel {Dactylocystis) (Fig. 247). 

 Ordovician ; Russia. 



Fui. 24t). 



Fig. 247. 



Proteroblastus schmidti Jaekel. 



Ordovician ; Estlionia ; amh, food- 



]'rotoi:rinites ovifonnis Ei('hwald. Ordovician; Pulkowa, Russia. grooves; hr, brachioles ; lamh, 



a, Calyx viewed from abo\e, ; b, Same from below showing basal inter-anibulacrals ; o, mouth (after 



l)late in the centre (after Volbortli). Jaekel). 



Mesocystis Bather (3Iesites Hoffmann ; Agelacrinus Schmidt). Ordovician ; 

 Russia. 



Family 4. Gomphocystidae Bather. 



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

 the brachioles. 



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

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

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

 America and Clotland. 



Pyrocystites Barrande. Ordovician ; Bohemia. 



