Ch. XIV.] MIOCENE STRATA OF BELGIUM. 237 



Koninck. Among them Leda (or Nucula) Deshayesiana (see fig. 

 170) is by far the most abundant ; a fossil unknown as yet in the 



Fig. 170. 



Leda Desliayesiana. Nyst. Syn. Nucula Deshayesiana. 



English tertiary strata, but when young resembling Leda amygdaloides 

 of the London clay proper (see fig. 256 p. 294). Among other char- 

 acteristic shells are Pecten Hoeninyhausii, and a species of Cassidaria, 

 and several of the genus Pleurotoma. Not a few of these testacea 

 agree with English Eocene species, such as Aciceon simulatus, Sow., 

 Cancellaria evidsa, Brander, Corbula, pisum (fig. 171), and Nautilus 

 (Aturia) ziczac. They are accompanied by many teeth of sharks, as 

 Lamna contortidens, Ag., Oxyrhina xiphodon^ Ag., Charcharodon hetero- 

 don (see fig. 240), Ag., and other fish, some of them common to the 

 Middle Eocene strata. 



Rupelian Clay of Hermsdorf near Berlin. — Professor Beyrich has 

 described a mass of clay, used for making tiles, within seven miles of 

 the gates of Berlin, near the village of Hermsdorf, rising up from 

 beneath the sands with which that country is chiefly overspread. This 

 clay is more than forty feet thick, of a dark bluish-grey color, and, 

 like that of Rupelmonde, contains septaria. Among other shells, the 

 Leda Deshayesiana before mentioned (fig. 170) abounds, together 

 with many species of Pleurotoma, Voluta, &c, a certain proportion 

 of the fossils being identical in species with those of Rupelmonde. 

 The succession of the Lower Miocene strata of Belgium can be best 

 studied in the environs of Kleyn Spawen, a village situated about 

 seven miles west of Maestricht, in the old province of Limburg in 

 Belgium. In that region, about 200 species of testacea, marine and 

 freshwater, have been obtained, with many foraminifera and remains 

 of fish. 



The following table will show the position of these Belgiau or Lim- 

 burg beds : — 



Upper Miocene. 

 A. Bolderberg beds, see p. 235, seen near Hasselt. 



Lower Miocene. 



b. : 



Nucula Loam of Klevn Spawen, same ) ^ T . 



age as the clay of Kupelmonde [^ Ll " lbur S beds.-Rupehan of 

 D , „ J \ Dumont. 



and Boom. ; 



B. 2. FluTio-marine beds of Bergb, Lctben, ) Middle Limburg beds. — Upper Ton- 

 and other places near Kleyn Spawen. \ grian of Dumont. 



