506 Vo7i Koenen — Belgian Tertiaries. 



different beds is mucli more considerable. The " Sable jaiine " 

 attains, near Denrne, a thickness above fifteen feet ; the " Sable 

 gris," in the new harbour (or dock?) between the town and the Fort 

 d'Austruweel, as far as I remember, about twice as much ; the 

 " Sable noir ; attains six metres near the fort (according to the 

 section of Captain Dejardin). 



I have collected in the Scaldisien beds between Deurne and the 

 Fort d'Austruweel the following species of bivalve shells, in a 

 splendid state of preservation, partly even with the ligament pre- 

 served : — Lingula Dumortieri, Nyst., Terehratula grandis, Blum., 

 Ostrea edulis/^ Pecten tigrinus, MiilL, Peden opercularis, L., Modiola 

 sericea, Goldf./^ Pinna sp., Leda sp.,^'^ Nucula s-p., Astarte Basteroti, 

 La Jonk.,* Astarte Omalii, La Jonk.,* Astarte Burtini, N., Cyprina 

 islandica, L., C. rustica, Wood,* Isocardia cor, Jj.J'' Artemis exoleta, 

 Lucina borealis,lj.,'''' Axinus sinuosus, Sow., * Tellina Benedenii, Nyst.,* 

 Solen. two sp.. My a truncata? L., Panopcea Menardiif Glycimeris 

 angusta, L., and many others. My collection and my books being 

 packed up, on account of leaving Berlin in order to settle at Mar- 

 burg, I am obliged to write down from memory only those species 

 about which I am quite sure. I mark by asterisks the species which 

 were rather common bivalves. 



I think there can be no doubt, first, that these species have lived 

 where I found them ; secondly, that some of them indicate a much 

 greater depth of water than Mr. Godwin-Austen gives credit for 

 in the Systeme Scaldisien ; and, thirdly, that they are not washed 

 out from the Systeme Diestien, in which, with few exceptions, they 

 do not occur at all. 



I have indeed seen, near Deurne, some Scaldisien beds, with 

 numerous broken shells, which undoubtedly were "terrains remanies." 

 but only by former fortification-works. A dead-shell gravel might 

 also be seen in a few places, but I have never found any shell in it 

 which was not common in the finer sandy beds in the neighbourhood. 

 Some beds near Deurne, several feet thick, consisted only of frag- 

 ments of Pecten grandis, P. striatus, P. opercularis, etc. ; but the 

 shells had been crushed at that very place, the pieces of every shell 

 lying flat together ; there was no clay or sand there to protect them 

 against the pressure of the overlying beds. The deepest cutting I 

 have seen was in the before-mentioned harbour (or dock) near the 

 Guano -magazine, north of the town. There was at the bottom, 

 still, fine grey sand with numerous specimens of Axinus sinuosus, 

 and Modiola sericea, and other shells, always having both valves. 

 Somewhat higher I have found several Panopcea, also, with both 

 valves, and still higher the Mya, oysters, Isocardia, etc., mostly with 

 both valves. 



It is very probable that some Scaldisien beds, particularly of the 

 Sable jaune, in the main ditch, indicate shallow water ; but others, 

 particularly of the Sable gris, undoubtedly have been deposited in a 

 similar depth as the Sable noir, so that the difference of fauna 

 between the Scaldisien and the Diestien cannot be explained by 

 difference of depth. I do not think that I have collected a single 



