PLATE XI. 



Fig. 1. POTERIOCRINUS DACTYLOIDES. 



1 a. — lateral view, exhibiting the aiTaiigement of the plates, the attachment of the rays, 



and column, and the base of the proboscis. 

 1 b. — portion of a ray with the tentacula attached. 



Fig. 2. POTERIOCRINUS PENTAGONUS. 



2 a. — lateral aspect shewing tlie arrangement of the perisomic plates, the pinnated rays, 



and tlie column. 

 2 b. — Tliis figure is introduced to show the manner in which the rays bifurcate, and the 



two additional branches, one on each side of the open space caused by the 



introduction of the inter-radial or non-bearing plates. 

 2 c. — lateral view exhibiting the inter-radial plates, and the additional bifurcations of 



the rays, and also the articulating facet of a columnar joint. 

 2 d. — lateral aspect of a specimen, shewing the tentacula. 

 2 e. — part of a proboscis which has been flattened out by pressure. 

 2 f. — base of attachment. 



Fig. .3. POTERIOCRINUS LONGIDACTYLUS. 



3 a. — lateral view showing the body, rays, tentacula, and column. This is drawn from 

 Mr. Morgan's specimen. 



Fig. 4. POTERIOCRINUS ABBREVIATUS. 



4 a. — lateral aspect shewing the arrangement of the perisomic plates, portions of the 

 rays, and column. 



Fig. 5. Synbathocrinus conicus. 



5 a. — lateral view shewing the rays, &c. 



5 h. — lateral aspect of a smaller specimen than the preceding. 



5 c. — this specimen shews the arrangement of the lateral plates. 



5 d. — represents the dorso-central plate, with the lateral plates attached to it. 



