744 W, P. SLADEN ON LEPIDODISCUS LEBOURI FROM 
57. On Lerrpopiscus Lrsourt, a new Species of AGELACRINITDE 
from the CarponirEeRous Series of NortHumBrrtanp. By W. 
Percy SiaDeN, Esq., F.G.S., F.L.S. (Read June 25, 1879.) 
[Prater XXXVII.] 
On this side of the Atlantic the Agelacrinitide are forms of the 
Echinodermata of such rarity of occurrence that each may well be 
spoken of as a veritable Phoenix amongst fossils! More than thirty 
years have elapsed since the first-discovered and hitherto solitary 
British species, Agelucrinites Buchianus, Forbes*, was found in the 
Bala Limestone of North Wales; and to this there can be added only 
two other forms, viz. A. bohemicus, Rémer+, from the Silurian of 
Bohemia, and A. rhenanus, Romert, from the Devonian of the Eifel, 
to make up a full list of the representatives of the group in Europe. 
Indeed so great is the rarity of these Cystideans that the number 
of individual specimens obtained from the whole area may literally 
be counted in units on the fingers alone. 
Turning, however, to the American continent, where Agelacrinites 
was originally made known, the group of species is found to be some- 
what more numerous, whilst forms occur amongst them which rank 
as allied genera§, and the vertical distribution extends from Lower 
Silurian up to Lower Carboniferous strata. 
The organism which furnishes the subject of the present com- 
munication was obtained at Kast Woodburn, in Northumberland, 
from a schistose limestone belonging to the Lower Carboniferous 
series, aud is especially interesting as being the first example of a 
Carboniferous form of the Agelacrinitidee occurring in Europe. We 
are indebted for the discovery of this remarkable Echinoderm to 
Prof. G. A. Lebour, of Newcastle-upon-Tyne, to whose energy and 
industry geologists already owe much information on the Carbo- 
niferous measures of the north of England. When originally found, 
the fossil was greatly obscured by adherent matrix, and further 
clearing seemed impracticable, owing to the extreme delicacy of the 
specimen. rom the imperfect examination only then possible, 
Prof. Lebour was led to refer the form to the fossil described by 
Meek and Worthen as Lepidodiscus squamosus ||, under which name 
he contributed an interesting note to the Geological Society of 
Belgium 4 upon its occurrence in England, and drew sundry infer- 
ences from its associations, 
* Mem. Geol. Survey, vol. ii. (1848), pt. ii. p. 521. ‘ 
t Recorded by Beyrich in Leonhard and Bronn’s N. Jahrb. f. Min. Geol. u. 
Petref., 1846, p. 192. 
t Verh. d. Naturh. Vereins f. Rhein]. u. Westph. 1851, viii. p. 857. 
§ Hemicystites, Hall, and Lepidodiscus, Meek and Worthen, comprise forms 
originally described as Agelacrinites. ¥ 
|| Proceed. Acad. Nat. Sci. Philad. 1868, p. 357; Geol. Sury. Illinois, vol. v. 
(1873) p. 513. 
| Ann. de la Soc. Géol. de Belg. t. iii, p. 21. 
