CLASS III 



CEINOIDEA 



231 



pyriform, attaining a large size, with proximal columnals flush with the 

 curvature of its sides ; in some others globose, with little enlargement of 

 the column. Upper face of the proximale marked by angular ridges corre- 

 sponding to the iiiterbasal suture lines. Radial facets wide, curved, 

 occupying entire distal face of plate. Primibrachs two, united by incom- 

 plete syzygy, closely joined laterally by suture, or occasionally connected 

 by small interbrachial s ; axillary and succeeding brachials united by muscular 



Fia. 335. Fig. 336. 



Fig. 335. 

 Ainocrinus parkinsoni Scliloth. Great Oolite ; Ranville, Calvados. A, Analysis of calyx, showing conrse 

 of canals. These are represented by dotted lines when concealed within the plates, and by heavy lines where 

 visible on the inner surface of the basals. B, Median longitudinal section throngh the uppeniiost stem-joints, 

 showing empty Space included between them ; &, Basal, seen fromabove and from the iiiside ; h*, Lower surface 

 (jfsame ; ri, Radial, seen from without; ri*, Inner aspect of same ; r^!, and r'^*, Corresponding views of first 

 brachial ; br, Arm-plates. (Canals are invisible in plates above the basals, except where they have become 

 exposed by weathering or abrasion.) 



Fi(i. 336. 

 Ainocrinus roissyanus d'Orh. Upper Jura (Coral- Rag) ; Tonnerre, Yonne. Restoration (after d'Orbigny). 



articulation, and all perforated by an axial canal, Arms dichotomous, 

 branching two or three times, pinnules strong. The column has a large opeii 

 Space in the expanded portion next to the calyx, the columnals sloping to a 

 thin edge toward the centre. Jurassic ; England, France and Switzerland. 



Millericrinus d'Orb. (Ceriocrinus and Pomatocrinus Desor, ex Koenig). Closely 

 allied to Apiocrinus, but the swelling of calyx plates afFects only one or two 

 columnals, and not any brachials, nor the distal border of the radials, which 

 remains narrow, so that the muscular articulation is of the usual type. 

 Calyx usually more or less globose or campanulate. Base occasionally with 



