334 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 19 



After examining with Captain Le Hon the principal points where 

 he had collected tertiary fossils in the neighbourhood of Brussels, I 



Table XII. and Fig. 7. — Subdivisions of the Middle Eocene Strata 

 near Brussels. 



. Thickness. 



ft. ft, 



I* Laekenbeds 10 to 25 E 1. Table I. p. 279- 



j c:^;:^^ "=i=^ 'C:::^) Upper Brussels sands, with oc- ■! 



J a <=^ c:::^ cz=^ casional calcareous concre- > 



1 5-^ <r=> ■=== "= tions J 



I J ^TTlJ7r:H^:-:^-"=^-^-'^'^— ^^ NummuUtes Imvigatus bed 



} 



III. 



Middle Brussels sands, fossili- 

 ferous, with calcareous con- ^10 

 cretions 



Lower Brussels sands, with^ 

 fTo jrC^ F"^^^ sandstone concretions, non- I _ , 

 *-*^ L/xr^ calcareous, or grotto-stones ( 

 ^^ CC:^ (g'r^s/^sir^) J 



,,^V<f"^',t";--'-"'v"/ "^^^^^^'^^ sand, without fossils . , 40 ^ 



E2. Table L 



Rock with Nu7n. planulatus . . 2 

 Sand with sandstone and casts ■) Un- ^E3. Table 

 of shells J known. 



Ie3. 

 1- J 



found it easy, with the aid of his museum, to subdivide the strata in 



Eocene beds, — a subject that has not as yet been satisfactorily treated, but towards 

 the elucidation of which I have to offer the following facts : — 



With Mr. Prestwich's kind assistance Mr. T. Rupert Jones has been enabled to 

 examine the typical specimens of the Nummuhtes referred to in the hst and de- 

 scription of the strata of the Alum Bay and White Cliff Bay Sections, pubhshed 

 in 1846 (Quart. Journ. Geol. Soc. vol. ii. p. 252 et seq. and PI. IX.) ; and this has 

 led to the correction of some of the specific names there assigned to the Nummu- 

 lites in question. By this examination Mr. Jones has found that in bed No. 11 of 

 the White Cliff Bay Section (i. e. in the equivalent of part of the Brackleshairi 

 series), NummuUtes variolarius (miscalled N. elegans, loc. cit. p. 254) occurs with 

 N. Icevigatus and N. scaber, — species which occur in two beds in contact wiih 

 each other at Cassel, as above stated (see p. 329). In beds 12 to 14, still higher 

 in the series, N. Icevigatus and N. scaber alone occur (as is also the case at Brackie- 

 sham) ; and yet higher, in bed No. 16 (probably a member of the Barton group), 

 N. variolarius (misnamed N. elegans, loc. cit.) occurs by itself, as in the upper- 

 most division of the Nummulitic Eocene of France and Belgium. In the Barton 

 Clay also (of Barton Cliff) N. variolarius is known to occur in great plenty and 

 by itself, as well as at Stubbington. 



There is also an important correction to be made in \he list of fossils accom- 

 panying the description of the Alum Bay strata, loc. cit. ^). 257, where two Num- 

 muUtes are given as occurring in bed No. 29 (generally .icknowledged to be the 

 equivalent of the Barton beds). The specimens in Mr. Prestwich's collection, on 

 re-examination, prove not to be, as there stated, N. latvigatus and N. elegans, but 

 one form only, and that hitherto undescribed. This little Numraulite possesses 

 characters distinct from those of A. variolarius, and somewhat approaches N. pla- 

 nulatus. In this circumstance we are reminded of the similarly anomalous posi- 

 tion of the NummuUtes planulatus, var. ? in the highest part of the Belgian Num- 

 mulitic Eocene, at Jette, as above noticed. 



I have elsewhere referred (p. 350, note) to the existence of N. planulatus {N. 

 elegans, ' Min. Conch.') at Emsworth, near Chichester. I may add that the-rock- 

 specimen in which it occurs is a siliceous grit, containing the Nummulite in great 

 numbers, together with casts of small gasteropods and bivalves. 



