348 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 19, 



to abound at an era more nearly corresponding with that of the 

 Bracklesham beds. I have already mentioned that in the Hill of 

 Cassel I found Nipadites, bored by TeredincE, at a somewhat higher 

 geological level, or in the beds containing Nummulites variolarius 

 (see p. 328). Teeth of Sharks occasionally occur in the same beds 

 with the Fruits at Schaerbeek, together with Ostrea flaheUula and a 

 Finna (P. margaritacea ?), showing that the water was salt ; while 

 the influence of a river is attested by the occasional presence of fresh- 

 water Tortoises. One of these, obtained by Captain Le Hon, exhibits 

 a perfect carapace, 1 foot long by 10 inches in breadth, and is pro- 

 bably the Emys Cuvieri, Galeotti, figured by Burtin. According to 

 Professor Owen, to whom it has been submitted, it is a perfect cast 

 of the inner surface of the carapace, with the hinder marginal plates 

 dilated, but in no part showing the scutation ; so that the species could 

 not be determined, although it may be pronounced to be " a freshwater 

 or estuary Emydian." 



I learn from Captain Le Hon that the marine Fish, figured by Burtin 

 in his ' Oryctography of Brussels,' plates 3 and 4 (Zeus auratus, 

 Blainville, and Pleuronectes maximus, Blainville), occur at the same 

 level as the Nipadites, Honium, and Emydian Tortoise above-de- 

 scribed. 



At Saventham, near Brussels, fossils similar to those at Schaerbeek 

 are found in a like position. 



[4.] Lower Brussels Sands with '^ grotto-stones,'"' &c. 

 (III. b. Table XII. p. 334.) 



The calcareous bands (III. a. Table XII.) last mentioned are about 

 10 feet thick. Below them, at Schaerbeek, other sands are found, 

 40 feet thick, with many layers (not less than twenty) of irregularly- 

 shaped nodules of sandstone, called pierres de grottes or gres lustre, 

 from the shining glossy lustre of the fractured surface. They consist 

 of aggregations of siliceous sand with a siliceous cement, such as that 

 which has petrified the fossil trees. The interior of a nodule is often 

 a cherty mass. The shapes of these stones are extremely irregular, 

 and sometimes quite grotesque. Sharks' teeth and shells, especially 

 Ostrea fiahellula and 0. virgata, are seen half-entangled in the solid 

 mass and half-projecting from the surface of the nodule, the loose 

 sand having fallen away from the exterior. Besides the more regular 

 beds of grotto-stones some scattered concretions occur, resembling the 

 branches of trees in shape. From the abundance of these in certain 

 districts the name of gres fistideux has been given to this division, 

 III. h. 



Below these beds are the sands III. c, which consist of white sili- 

 ceous sands without fossils ; and below these a stratum of rock with 

 Nummulites planulatus has been found by boring at Schaerbeek at 

 the depth of 70 feet, to which I shall presently allude. 



[5.] Dieghem Schistose Tripoli. (Table XII. III. a, and fig. 9, p. 339.) 



In the Dieghem quarries already mentioned, which are above 60 feet 

 in depth, immediately under the Nummulites Icevigatus bed I found 

 continuous beds of siliceous or cherty stone, 4 feet thick, one of which 



