CARBONIFEROUS FOSSILS OF IRELAND. 177 



Platycrinus punctatus. M'Coy. (PL XXV. figs. 15-17). 



Sp. C/i. — Pelvis very thick, rugged, concave in the middle ; scapulas of equal length and breadth, veiy 

 thick ; all the plates ornamented with equal, close, minute, elevated puncta. 



This species is chielly distinguished from the P. rugosus by its beautifully granulated plates ; from the P. 

 gramdatus it differs in the shortness of the scapulae, the largeness of the scapular articulations, and the greater 

 closeness and minuteness of the puncturing of the plates. The pelvis is small, but thick, rugged, and concave, 

 except at the edges ; the scapulse are very massive, of about equal length and breadth ; the articulation from 

 the cuneiform armjoint very large ; interscapulary plates large, pentagonal. Length eleven lines, width nine 

 lines. 



Platycrinus rugosus. Mill. 



Platycrinites rugosus. Mill. Hist. Crin. — Platycrinus rugosus. Phil. Geol. York Platycrinus rugosus. 



Portk. Geol. Rep. 



Sp. Ch. — Pelvis very flat ; scapulae square, very thick, rugged, surface smooth ; three fingers to each hand ; 

 scapular articulation very large and low. 



The pelvis and scapulae are very thick, variously ornamented, according to the degree of muscular con- 

 traction ; in some cases they are quite smooth, with steeply-bevelled edges, at other times they are rugged, with 

 variously shaped protuberances, but in all, the surface, when examined with the lens, appears smooth. 



Platy'crinus siMiLis. M'Coy. (PI. XXVI. fig. 6). 



Sp. Ck. — Pelvis truncated, flat; scapulas narrower above than below; length of the scapulae about two- 

 thirds the width of the pelvis. 



This species very closely resembles the P. contractus, but is distinguished by its perfectly flat pelvis, and 

 the shortness of its scapulas. Length five lines, width seven lines. 



Platycrinus triacontadactylus. M'^Coy. (PL XXV. figs. 2-7). 



Sp. Ch. — Plates of body smooth; scapula of equal width throughout, each supporting an arm with two 

 hands and three fingers each. 



This species could scarcely be distinguished from the P. IcBvis, were it not for the addition of a third lateral 

 finger to each hand. It occurs in company with that species at Hook Head in Waterford, in which re- 

 markable locality, specimens of both those species and many others are found beautifully preserved, with 

 their column, body, proboscis, hands, tentacula, &c. quite perfect and in situ. The proboscis is very large, 

 composed of smooth, polygonal plates ; it Is obtuse at the apex, where the opening appears as a simple slit, 

 bounded by four quadrangular plates ; the fingers are beautifully tentaculated ; the column is round near the 

 pelvis, and formed of joints, alternating a longer and thicker with a shorter and tliinncr, every seventh one being 

 a little larger ; at this portion of the column the joints articulate by a radiatingly striated margin only ; lower down, 

 the joints become elliptical, and the transverse ridge characteristic of the genus appears. Length of body from 

 the base of arm-joint to base of pelvis three lines and a half; width seven lines; length of proboscis one inch 

 four fines. Since the plate of this species was printed, Mr. Austin has desci-ibed (An. Nat. Hist., vol. xi.) a species 

 under the name of P. trir/intidacfi/lus, which may be identical with this; as the description is not very full, and 

 there is no figure, I am not certain of the fact. 



Platycrinus tuberculatus. Mill. 



Platycrinites tuberculatus. Mill. Hist. Crin. — Platycrinus tuberculatus. Phil. Geol. York. 

 Sp. Ck. — Cyfindrical, pelvis abruptly truncated, nearly flat, scapulae lengthened, equally wide above and 

 below; marked with irregular rows of tubercles. 



2 Y 



