582 A. W. GRABAU LOWER ORDOVICTC FORMATIONS 



found in some American sections, and due to the same eustatic movement. 



In the Iberian chain of the ancient province of Aragon the Armorican 

 sandstone is only about 30 meters thick and rests on a ferruginous upper 

 member of the Cambric, the hiatus between the two being somewhat 

 marked. This is followed by the Angers slates, 25 to 30 meters thick, 

 and characterized by Calymsne tristani Bron., Ortliis budleighensis Dav., 

 Redonia, etcetera. A 12-meter bed of unfossiliferous quartzites sepa- 

 rates this from shales with Ortliis actonice Sow., 0. altemata Sow., Or- 

 tliis budleighensis Dav. This is probably the Ashgill horizon. Beds of 

 this age with Ortliis actonice, 0. cf. vespertilio, Strophomena expansa, 

 Tentaculites, Ghcetetes, Favosites, and Strophe-stylus form the oldest fos- 

 siliferous horizon of the Pyrenees. 



In the Sierra Morena and the mountains south of Toledo beds of the 

 age of the Angers slates and the May sandstone (Llandeilo) are known, 

 resting on a thin quartzite with Cruziana, which may represent a part of 

 the Armorican grit. The Arenig series seems to be largely wanting here, 

 either through non-deposition or on account of erosion during the re- 

 treatal interval. 



The fossils found in the Orclovicic beds of this southern half of Spain 

 are all from the beds belonging to the higher or retransgressive series. 

 These include : 



Placoparia tournenvinei M. Rouault. 



Cheirurus marianus de Vern. 



Homalonotus rarus Oorcla. 



H. brongniarti Desl. 



Galymene pulhra Barr. 



G. (Sgnhomalonotus) tristani Brong. 



C. aragoi M. Rouault. 



G. tristani de Vern. et Barr. 

 Dalmanites socialis Barr. 



D. dotvningiw Murch. 

 D. vetillarti M. Rouault. 



D. torruMcs de Vern. et Barr. 



D. phillipsi Barr. 



D. dujardini M. Rouault. 



Lichas hispanica de Vern. et Ban - . 



Trinucleus goldfussi Barr. 



Asaphus nobilis Barr. 



A. cianus de Vern. et Barr. 



Asaphus contractus de Vern. et Barr. 



A. glabratus Sharpe. 



lllwnus hispanicus de Vern. et Barr. 



111. sauchesi de Vern. et Barr. 



