qq potekiocmnn)^.— poteriocrinus. 



Synonymes and References. 



Poteriocrinus dactyloides. — Austin, Ann. iSf Mag. Nat. Hist. Vol. 10. p. 108. Sf Vol. 11. 



p. 197. 



Formation and Localities. 

 Mountain Limestone. — Hook Point, at the entrance of Waterford Haven. 



Tlie P. Dactyloides is a small species, none of the specimens yet developed exceeding 

 in size that from which figure 1 a, plate 11 was drawn. In the arrangement of its rays 

 it very slightly approaches to the Synhathocrinus. 



The rays are undivided and long in proportion to the size of the body. Their number 

 and arrangement in small specimens have some faint resemblance to a long bony human 

 hand, which circumstance has suggested the specific name. 



The proboscis is large and its plates crossed by elevated striae. 



The upper portion of the column is composed of thinjoints, every fourth articulation 

 being somewhat thicker than the intervening ones. The lower portion is probably equal 

 jointed as in most of the genus. 



We have obtained several specimens of the P. dactyloides, from the mountain limestone 

 of Ireland, but its occurrence in other mountain limestone districts, has not been clearly 

 ascertained. The rarity of the species, may perhaps be attributed to the fragmentary 

 state in which it generally occurs, rather than to the confined limits of its former 

 existance. 



13. Species. Poteriocrinus pentagonus. (Austin.) 

 PL U.fg. 2 a, 2b, 2 c, 2d, 2 e, 2 f. 



Definition. — Lateral plates much shorter than in the typical species; mouth centrical 

 and elongated into a proboscidiform tube ; rays articulating to the body, by the whole 

 breadth of the ray bearing plates, total number of rays twelve] tentacula numerous ; 

 column long, and composed of numerous thinjoints. 



