Faher & Spencer — Deep Boring in Denmark. 171 



work on Edrioaster, naturally found difficulty in describing his 

 imperfectly preserved specimens. The suhvective skeleton has the 

 normal Edrioaster structure, and the so-called ' subambulacral plates' 

 marked ' » ' in pi. iii, tig. 4, are incorrectly drawn. The absence 

 of evidence for a contrasolar ray has already been alluded to (p. 122). 

 Tlie ' triangular oral plates ' are presumably the interradial elements 

 of the mouth-frame. Tlie cover-plates slope from their outer margins 

 towards the oral pole ; those pushed into the groove tend to imbricate 

 adorally. 



The original specimens came from sandstone in the Snake Hill 

 shales of Saratoga Co., N.Y. These beds are supposed to lie just 

 above the Basal Trenton, and below the Prasopora zone. The species 

 is therefore the oldest of the four here discussed. 



Edrioaster levis n.sp. 



An Edrioaster with height of theca about one-third of diameter, 

 peripherj' roughly circular; with rays scarcely raised above general 

 surface, and floor-plates not clearly demarcated from interradials ; 

 rays all have a solar curve ; interradials faintly scrobiculate, not 

 pustulate. 



Holotype, Brit. Mus. E 15900. 



EXPLANATION OF PLATES. 



Plate XIII. 



Edrioaster bigsbyi. The adapical face of specimen C, of the Canadian 



Geological Survey, showing the peripheral portions of rays I-V, the 



eleven large frame-plates, and the lobed evagination of the central 



integument, the small plates of which are not clearly seen, x 3 diam. 



Plate XIV. 

 Edrioaster bigsbyi. 



Fig. 1. The adapical face of E 15930, with same orientation as 

 Plate XIII. The minute plates of the central integument are well shown. 

 In the place of the frame are the circular elevations of this integument 

 described on p. 169. Photographed by Mr. H. G. Herring, x 3 diam. 



Fig. 2. Part of the circumoral region of the test of E 16172, seen from 

 the interior, as described on p. 165. Drawn by Mr. W. G. Browning. 

 X 3 diam. 



Fig. 3. Some floor-plates of E 16172, showing the ridges that lead 

 from the peripodia to the perradial channel. Drawn by Mr. G. C. Chubb. 

 X 10 diam. 



V. — Some Notes on a Deep Bohing througu the Chalk of 



IJknmark. 

 By H. Faber, F.C.S., and W. K. Spencer, M.A., F.G.S. 



EARLY in the year 1913 the Copenhagen Mn,scum of Mineralogy 

 and Geology issued a report' upon a 7uost interesting deep boring 

 in the Chalk at Grondal, just outside Copenhagen. The results are 

 so striking in respect to the thickness of chalk passed througli that 

 it appears desirable to bring them before the notice of Englisli 

 geologists. The estimates of the thickness of the English Chalk 



' Dybdebormg ved Kobenhnrn, 1894-1907, ved E. P. Bonnesen, 0. B. 

 Boggild, og J. P. J. Ravn, Copenhagen, 1913. 



