Palaeontology. — "Contributions to our Knoio/edijf of the /'aide- 

 ontology of the Netherlands". II. "On the Fauna of tlie t'hos- 

 phatic Deposits in Tinente. {Lower Oligocene)" By (). Posthumus. 

 (Coiniiumicated hv Piof'. J. F. van Bbmmklkn). 



(Gommiiiiioated at Ihe meeting of March 24, 1923j. 



In examining a collection of fossils, derived fioni the phospliatic- 

 nodnlus-bearing deposits of tiie localities Ootmaisum and Ro.ssnm 

 (between Oldenzaal and Denekauip) I came npon tlie following 

 formations : 



Coelotnn ba/ticuni Schlutkh, Zeitsdirift der dentschen Geol. Ges. 

 Bd. 31, 1879, p. «04, PI. XVIII; one specimen. 



Myliobates toliapicus L. Aüassiz, Recherches snr des Poissons 

 fossiles, vol. 3, 1843, p. 321, tab. 47, fig. 15— 20; loose toothplates. 



Carcharodon angitslidens L. Agassiz, Recherches etc., vol. 3, 

 1843, p. 255, tab. 'fig. 20—25, tab. 30, fig. 3; teeth. 



Notidan.ns ])rimiyenuis L. Agassiz, Recherches etc., vol. 3, 1843, 

 p. 218, tab. 27. fig. 4—8, 13-17; teeth. 



O.vyrhina Desori (L. Agassiz) Sismonda, Memoria della Reale. 

 Accadeinia delle Science de Torino, 2d series, t. X, 1849, |i. 44, 

 tab. II, tig. 7—16; teeth. 



O.ryrhina Desori L. Sismonda iniit. tlandrica, M. Lkkiche, Mé- 

 moires dn Miisée Royal d'histoire naturelle de Belgiqne, T. 5, [>. 

 280, fig. 87; vertebrae. 



Odontaspis cuspidata L. Agassiz, Recherches etc., vol. 3, 1843, 

 p. 294, tab. 37, fig. 43—49; teeth. 



Otodus obliquus L. Agassiz, Recherches etc., vol. 3, 1843, p. 

 267, tab. 31, tab. 36, fig. 22—27; teeth. 



Lamna spec, vertebrae. 



Phyllodus polyodus L. Agassiz, Recherches etc., vol. 2, 1843, 

 p. 240, tab. 69a, fig. 6, 7; 



And in addition some fragments of bone, presumably from Cetacea. 



The phosphaiic deposits are disposed in the profile as follows'): 



"Underlying the .\Iiddle-Oligocene Septarian clay are pale- 

 green, very fine glauconite sands, probably referable to Lower- 

 Oligocene, but seeming to belong (o the Middle-Oligocene. At the 

 basis of these sands a very typical conglomerate layer of loosened 

 phosphorite nodules and shark's teeth appears, as may be found 

 e.g. in the eocene quarries at the southern base of Lonnekerberg 

 in the neighbourhood of Rossum, between Oldenzaal and Denekamp, 

 and in the hills north of Ootmarsum". The phosphatic deposits 



^) Eindverslag van de Rijksopsporing van Delfstoffen. Amsterdam, 1918, p. 114. 



16 

 Proceedings Royal Acad. Amsterdam. Vol. XXVI. 



