T. Davidson — On Tertiary Brachiopoda. 151 



Messrs. L. de Koninck, Dewalque, Vincent, Lefevre, and Colbeau 

 for the loan of specimens forming part of their collections. 



The Tertiary series is pretty well represented in Belgium, and in 

 his •' Eapport Seculaire sur les travaux de la Classe des Sciences de 

 I'Academie Eoyale de Belgique" (pp. 59-61. 1872) M. Dewalqiie 

 publishes a table showing the classification of the Tertiary deposits 

 of Belgium, as compared with those of the basins of London and 

 Hampshire. 



In 1852 M. Dumont divided the Tertiarj^ formations of Belgium 

 in the following manner : — 



p \ Systeme Scaldisien. | — our Crag. (The Syst^me Diestien is now 



PLIOCENE I Systeme Diestien. \ considered to be Upper Miocene. T.D.) 



Miocene Systeme Bolde'rien = Faluns of Touraine ? 



Upper Eocene ouVg ^v j^yp^iien = Upper Lacustrine deposit and sands of 



LowEK Miocene f > ^ Fontainebleau. 



yy -, ( Systeme Tongrien = Lacustrine deposits of the Isle of Wight. 



UPPER iiocENB I gyst^jjjg Laekenien = Sands without fossils of Hordwell, also 



Barton Clay. 



i Systeme BruxelUen = Calcaire Grossier, Bracklesham Sands, and 

 Baffshot Sand. 

 Systeme Paniselien 

 Systeme Ypre'sien — Bognor Clay, London Clay. 

 LowEK Eocene Systeme Landenien = Plastic Clay. 



Cretaceous. 



In a letter dated the 2nd of April, 1873, M. Nyst gives me his 

 views relative to the divisions of the Tertiary formations of Belgium, 

 and I have added the names of the Brachiopoda that occur in each of 

 these divisions. 

 Pliocene, 



Upper division. Does not exist in Belgium. 



Lower division. Composed of yellow and grey sands. The 

 yellow sands occupy the upper portion, and are the equivalent of the 

 Crag of Norfolk and Sutton. The grey sands should perhaps be 

 considered to represent the Coralline Crag. In this last we find — 1. 

 Lingula Dumortieri, 2. Terehratula grandis, 3. Terebratulina caput- 

 serpentis, 4. BhyncJionella Nysti, and 5. Mh. psittacea ? 

 Miocene = Systeme Diestien of Dumont. 



The upper portion is composed of the black sands (sables noir) of 

 Diest, and of Antwerp. This deposit seems to be wanting in Great 

 Britain. It contains the Mannia Nysti of Dewalque. 



The lower division of the Miocene formation is represented in 

 England by the marls of Henis in the Isle of Wight, and in which 

 fresh and brackish- water shells abound. It contains no Brachiopoda. 

 The sands of Lethen and of Hoesfelt have hitherto afforded no other 

 species of Brachiopoda besides the Discina Suessi and Terebratulina 

 ornata. M. Nyst believes this last named bed to represent the 

 Barton Clay of England. 

 Eocene. 



The upper division of the Eocene formation is wanting in Belgium. 



The Middle Eocene is composed of the sands of Laeken, with 

 Nummulites planulata, var. minor. It is the equivalent of the Brackle- 



