Vol. 54.] 



AND THE CORALLINE CRAG. 



3m 



The fauna of this zone resembles generally that of the Coralline 

 Crag, but it contains a few Miocene species not known from, or 

 rare in, that formation, such as Pyrula reticulata,^ Cassis Sahuroriy 

 Murex scalar if or mis, Conus Dujardinii, and Pleurotoma intorta. 

 On the whole, it presents a somewhat more recent facies than that 

 of Lenham, although it seems older than the Coralline Crag. 



M. Van den Broeck has, however, discovered a fossiliferous bed at 

 Waenrode, near Diest, from which the following species have been 

 obtained : — 





Extinct 



Cor. Crag 



or 

 Diestien 



Lenham 

 or Box- 

 stones 



Miocene 



Cassis Saburon, Brug 



* 



* 



* 



* 

 * 



* 

 * 

 * 

 * 



* 



* 



* 

 * 



* 

 * 



* 

 * 



t „ Rondettii (?) Bast 



Pi/ruta reticulata, Sism 



Aporrhais pes-pelicani, Linn 



Turritella incrassata, Sow 



Scaphander lignarius (?) Linn 



'\Tecten Caillaudi (?) Nyst 



Nucula Icevigata, Sow 



Leda semistriata, S. V. W 



Cardium suhturgidum, d'Orb 



Lucina horealis, Linn 



t „ Di'ouetti (?) 'Njst 



Cryptodon flexuosum, Mont 



Isocardia lunulaia, Nyst 



Cytherea ritdis (?) Poli 



Tellina compressa, Broc 



Abra ]ms/nat/ca, Mont 



Cultellus tenuis, Phil 



Gorbula striata, W. & B 



Teredo, sp. 



If it were not for the presence of the three species marked f, the 

 identification of which seems to be uncertain, this group of fossils 

 would be as nearly related to the Pliocene as to the Miocene. Out 

 of the 19 species named, 14 occur also in the Coralline Crag and the 

 Diestien, and 16 in the Miocene of Belgium ; but there are 3, 

 Leda semistriata, Tellina compressa^ and Cultellus tenuis^ that are 

 not known from the last-named formation. If we omit the doubtful 

 species, the proportion is 13 out of 14 in the former case, and 11 

 out of 14 in the latter. The percentage of Coralline Crag forms 

 generally in the Belgian Miocene is very different. M. Van den 

 Broeck enumerates 175 species of moUuscafrom the Miocene zone a 

 Panopcea Menardi, only 79 (or 45 °/o) of which are found in the 

 Coralline Crag, and 143 from the zone a Pectunculus pilosus,^ 

 only 77 (or 53 7o) of which are common to that deposit. The list 



^ Pyrula reticulata and Pleurotoma intorta are, however, found also in the 

 z o n e a Isocardia cor. 



2 ' Esquisse Geol. & Pal^ont. des Depots Plioc. d'Anvers,' 1876, pp.42 & 56. 



Q. J. G. S. No. 215. 2 a 



