J. W. Jackson — Palceontological Note*, Manchester Museum. 403 



much less, the carination is not so prominent, and it is a perfectly 

 smooth shell, lacking the characteristic striae of P. umbilicatus. The 

 example in our collection, which we take as the type, measures 

 12x2 mm. It is not improbable that this Crag shell is the ancestor 

 of the recent form, but better examples of P. umbilicatus (Mull.) 

 from the Forest Bed (Cromerian) are needed before one can state 

 definitely whether this view be correct. 



V. — Pal^ontological Notes from the Manchester Museum. 



Archjeocidams in the Middle Coal-measures of Lancashire ; 



with Notes on other Species. 



By J. Wilfrid Jackson, F.G.S., Assistant Keeper, Manchester Museum. 

 1 N the course of working through the large collection of Coal- 

 JL measure fossils in the Manchester Museum I have recently 

 discovered a 7iumber of interesting, and hitherto unrecorded, forms 

 from the well-known ' Marine Band ' in the Middle Coal-measures 

 of Ashton-under-Lyne. The most interesting of these additions is 

 undoubtedly Archceocidaris, a genus which is not at all common in 

 the Coal-measures of this country, though fairly abundant in North 

 America. Hitherto it has only been recorded from the North and 

 South Staffordshire Coal-fields ; its discovery, therefore, at Ashton 

 constitutes the third record for the British Isles. 



With the possible exception of the two forms of Orthoceras, which 

 require further study, all the species mentioned below have been 

 recorded from the Marine Band below the Gin Mine Coal, North 

 Staffordshire Coal-field, and their occurrence in the Marine Band 

 at Ashton, Lancashire, affords further confirmatory evidence of the 

 correlation of these two bands. 



Other species already recorded from the Marine Band at Ashton 

 and Dukinfield are Ctenodonta lecvirostris, Pseudamusium fibrillosum, 

 Pterinopecten papi/raceus, and Listr acanthus, specimens of which are 

 in the Manchester Museum. 



Echinodermata. 

 Arch(SOcidarts sp. This is represented by a fragment of the basal 

 portion of a spine, its length being about 10 mm. Immediately above 

 it is the cast of some 15 mm. more of the same spine, and just below 

 is the impression of the basal end. The spine is very like that figured 

 from below the Gin Mine Coal, North Staffordshire Coal-field, 1 and 

 possesses similarly disposed spinules. The specimen forms part of the 

 ' Wild Collection ', and was obtained from the Marine Band (450 feet 

 above the Great Mine Coal) at Ashton Moss Colliery. 



Brachiopoda. 



Orbiculoidea nitida (Phill.). After careful study I am unable to 



separate Piscina orbicularis, Bolton, 2 recorded from the Ashton Moss 



Marine Band (Cairns Collection) and roof of the Bullion Coal, Carre 



Heys, Colne (Wild Collection), from dwarfed or immature examples 



1 Q.J.G.S., vol. lxi, p. 529, pi. xxxv, figs. 1, la, 1905. 



' 2 Manch. Memoirs, vol. xli, No. 6, pp. 2, 3, pi. v, figs. 1, 2, 1897. 



