333 I'hk Oligocene of the Southern United States 23 



Bithinia teyiuiplicata G. Vin. Bithinia helHcella Braun. 



" inflata Braun. Cardium scobimda Mer. 



The clays of Henis. The clays of Henis, so named because 

 of the large brick and tile factories near that town, vary from 

 pure plastic green clays, of great economic importance in tile 

 making, to brownish black, sandy beds. The purer clays are 

 found towards the upper part of the deposit. These are quite 

 unfossiliferous and hence most valuable, because the presence of 

 a single fossil is ruinous to a tile, since the lime becomes calcined 

 in baking and leads to the disintegration of the tile. The sandy 

 clays occurring towards the base of the formation often contain 

 fossils, many of which are washed in from other beds, but Cythe- 

 rea iucrassata is sometimes found in place. While the clays of 

 Henis have no really chara(5leristic species, some forms, rare in 

 the underlying sands of Bautersem, become very common in the 

 clays. Among these are Neritina Duchasteli Desh., Modiola 

 Faujasi Brongn. and Corbula pisum Sow. Other species abund- 

 ant in the claj^s are 



Bti.ccinum Gossardi Nyst. Natica Ny sti d,^ Ox\) . 



Cerithium trochleare Lam. Odostomia Sernperi Bosq. 



" cancelliniim G. Vin. Turbonilla Icevissima Bosq. 



Cardi2un Kochi Semper. Cyrena negleH-a Nyst. 



Bithinia Duchasteli Nyst. 



The sands of Vieuxfoncs. The sands and marls of Vieux- 

 Joncs (Oude Biesen) are very fossiliferous, and the shells are best 

 preserved in the park of the Chateau. Unfortunately, the writer 

 found the park closed in the absence of the owner, but the same 

 beds were observed further along the road. In this locality the 

 marl was formed almost entirely of organic remains of which 

 Cerithium elega?is formed a large proportion. C. Lamajcki and 

 C. plicatum were also observed in considerable numbers. The 

 fauna of the Vieux- Jones region is rich, but not varied, and com- 

 prises only about 50 species. 



The charadleristic species are 



Buccimun Thierensi Bosq. Cerithium limula Desh. 



Teiyiostoma decussaticm Sandb, Bulla ininima Sandb. 



