340 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 19, 



patelliform, depressed; vertex almost central; surface exteriorly 

 unequal and rugose. Interior of upper valve (the only one known) 

 concave, margin narrow, granulated. Four muscular impressions ; 

 the posterior ones are more or less circular, lying close to the inner 

 edge of the granulated margin, and separated from each other by a 

 flat space not equal in size to one of the muscular impressions ; the 

 anterior pair are irregularly oval, diverging from near the centre to- 

 wards the posterior lateral margin : a slight prominence existing 

 before the central pair. Vascular impressions not well defined. 

 Structure punctuated. Length 4 lines. Breadth 4^ lines. Depth 

 1 line. 



Locality. Eocene beds of Dieghem, near Brussels, and in the beds 

 of the Hill of Turin. 



Fossil Echinoderms. 



In the foregoing lists of fossils from the Upper Brussels sands, the 

 names of six species of Echinoderms have been enumerated ; and I 

 have mentioned, besides, the Echinolampas Galeottianus, as found a 

 few feet above the Nummulite~bed at Cassel. Excepting E. ajffinis ?, 

 figures of all these are given in PL VIII. ; and Professor E. Forbes 

 has had the kindness to draw up the following descriptions. 



Note on the Eocene Echinoderms procured by Sir Charles 

 Lyell in Belgium. By Professor E. Forbes, F.R.S., F.G.S. 



In M. Galeotti's Memoir on the Geology of Brabant, he enu- 

 merates eight species of fossil sea-urchins, and figures seven of them 

 as new, but without detailed descriptions. The figures are very 

 slight, and, in the present state of the subject, insufficient. x4.dditional 

 representations of these interesting fossils are, therefore, much to be 

 desired, and some additional information respecting their characters 

 cannot fail to prove useful. 



Sir Cbarles Lyell has submitted to my examination seven tertiary 

 Sea-urchins from Belgium (exclusive of Echinolampas affinis T) . All 

 but one among these appear to be identical with Galeotti's species. 

 They are represented in PL VIII. of this volume. 



Echinolampas Galeottianus, n, sp. PL VIII. fig. 1, a, b, c. 



These figures represent an Echinolampas not included in Galeotti's 

 list. It was found in abundance by Sir Charles Lyell in the Hill of 

 Cassel, near Dunkirk, and named for him by some of the Belgian 

 naturalists, Clypeaster (i. e. Echinolampas) affinis of Goldfuss. It 

 differs in some material points from the figure of that species in the 

 ' Petrefacta Germanise,' and, as several very perfect specimens have 

 been submitted to my examination, all of which exhibit the same 

 features, I feel warranted in regarding them as examples of a distinct 

 form of this genus, and to which, as the species appears to be unde- 

 scribed, I would assign the name of Echinolampas Galeottianus. 



A large example measures 2\ inches in length by 'iy^^ths in breadth. 

 Its greatest thickness (somewhat in front of the apex) is yfths of an 



