71 



II. SPECIES POTERIOCRIN1TES TENUIS. 



THIN VASE-LIKE LILY-SHAPED ANIMAL. 



Specific Character. 



A Crinoidal animal with a column formed of numerous round thin joints, 

 surface of articulation radiatingly striated. The plate-like joints forming the 

 cup-like body, articulating by minute strias. One arm proceeding from each 

 scapula supporting two fingers. 



Locality. 



^ 



In the Mountain Limestone of the Mendip Hills, and in the Black Rock 

 (the fourteenth bed of Dr. BKIGHT'S series; see Geol. Trans. VOL. iv. p. 193.) 

 near the river Avon, Bristol, belonging to the same formation. 



Description. 

 It is a much neater and smaller species than the former. 



Its COLUMN (fig. 1.) must have possessed near the summit a considerable 

 degree of muscularity, since the thin joints of this part appear to have yielded 

 to the impression of the lower part of the pelvis joints, and the pressure of the 

 muscle acting on them, so as to assume a slightly-waved marginal outline. 



The PELVIS (fig. 2. to 5.) together with the five intercostals (fig. 6. and 7.) 

 and the scapulae (fig. 8. and 9.) adhere by slightly striated surfaces, and \vilh 

 the intervening pentagonal and hexagonal plates form a small and elegant trun- 

 cated cup. 



The ARMS (fig. 12. to 21.) From the scapula proceeds immediately the 

 cuneiform joint of the arm, it is very slender and loug, yet in general construe- 



