POTERIOCRINID.E. — POTERIOCRINUS. 77 



additional side arms are also produced, and thus the exact relation between the claspers 

 and the length of the column is constantly maintained. 



In order that the objects which came within the folds of the side arms might be more 

 firmly retained, each joint has on its upper side, or that side which is next towards the 

 column when the clasper is in a vertical position, an overlapping edge with a narrow raised 

 ridge which runs parallel to the articulations, and by which means it could the more firmly 

 maintain its hold of any extraneous object it might have grasped. Vide PI. 9. fig. 2, g. 



The rays are long, and composed of single series of wedge shaped joints, each of 

 which is furnished with a lateral tentacula. 



The primary rays are five, and the smaller divisions apparently amount to ten. These 

 latter are deeply sulcated as in the typical species. 



We are indebted to the kindness of Miss Rich for the opportunity afforded us of adding 

 figures 1, and 2, a, plate 9. to our illustrations. The specimens from which figures 

 pi. 9. 2, b, to 2 f. are taken, were developed by the Authors from the mountain limestone 

 of Ireland. 



4. Species. Poteriocrinus granulosus. (Phillips.) 

 PL 9.fg. 2 a, to 2 f. 



Definition. — Body hemispherical ; ray bearing articulations extending the whole bread tli 

 of the plate ; colunm large. Number of rays unknown. 



Stnontmes and References. 



Poteriocrinus granulosus. — Phill. Geol of Yorlc. PI. 4, fg. 2. Sfc. page 205. 

 Cap encrinite. — Parkinson's Org. Rem. Vol. 2. PI. 15,/. 9, p. 194. 



Parkin. Outl. Onjcto. PI. 9,f. 4. 



Formations and Localities. 



Mountain limestone. — Derbyshire ; Yorkshire ; Belmore Mountain, near Enniskillen ; 

 Hook point, Wexford ; Mendips ; and in the vicinity of Kirkaldy. 



