rLATYCUIXlD.i:. ri-ATYt^RINLS. 



8. Species. Pi.atycrinus Striatus. (Millet:) 

 PL in. fig. 3, p io. u. 



Definition. — Dorso-central plate pentagonal, with a projecting rim for the attachment 

 of the column. The five perisomic plates are narrower than in the tj'pical species. 

 Rays twenty. Column similar to others of the genus. All the plates which envelope 

 the abdominal bulb are finely striated. 



Synonymes and References. 



Platycriuites striatus. — Miller. Nat. Hist, of the Crinoidea, p. 82. 



Messrs. Austin. Ann. ^ 3Iag. Nat. Hist. vol. 10, No. 63. p.l09. 



Blain. 3Ian. d'Act. p. 262. 

 Platycrinus striatus. — Koninck. t. F. fig. 3, a, b, p. 44. 

 Encrinites striatus.— Schloth. Nacht. HI. p. 94, PL 2Q,fig. 4, a, b, c. 

 Platycrinites striatus. — M. Edw. ap. Lamk. 2, p. Qi&Q. 



Formation and Localities. 



Carboniferous or Mountain Limestone. — The Black Rock, and Leigh Downs, Avon 

 side, Bristol ; Broadfield Down ; and Hook Point, Wexford. 



This species was probably extremely local, as its remains are not so widely diffused, 

 or so abundant as some of the other species of Platycrini. 



Description of the Calcareous Frajie Work. 



The Dorso-central Plate — Is hemispherico-conical, with a small projecting circle 

 of attachment for the slender column. The five most conspicuous elevated ridges which 

 ornament the plate, radiate from the columnar point of attachment to the five points 

 of the pentagon, numerous fine strife follow the same direction, and many other delicate 

 ridges run parallel to the border. 



