ARIETITES BUCKLANDI. 271 



Arietites bisidcatus has a quadrate angular form, with from forty-four to fifty ribs, 

 with a tubercle on each near the angle of the siphonal border, from whence they curve 

 forward into the sulcus. 



There is no other form in the Lower Lias for which Arietites BucMandi can be 

 mistaken. 



Locality and Stratigraphical Position. — Arietites Bucldandi characterises an impor- 

 tant zone of life in the English Lias, the stratigraphical relations of which are best 

 exposed in the magnificent coast section near Lyme Regis. I have collected this 

 Ammonite at Fretherne Cliffs, on the banks of the Severn, and fragments of it from the 

 Lower-Lias Limestones in the counties of Glamorgan, Somerset, Gloucester, Worcester, 

 and Warwick, and from the same formation where it is worked at Scunthorpe in the 

 north-west of Lincolnshire ; and also where it is exposed at Redcar, and Robin Hood's 

 Bay, on the Yorkshire Coast. The finest specimens I have obtained were found on the 

 coast near Lyme Regis, and in the Great Western railway cutting, in the Lower Lias, 

 at Salford, near Bath. Several fine specimens are preserved in the collection of the 

 British Museum. 



Foreign Distribution. — The two varieties of this Ammonite have a very w r ide range in 

 space, and form conspicuous leading fossils in the horizon they characterise. In France 

 it has been collected at Saint Rambert, Ain ; Paillet, Mont-d'Or, Saint Fortunat pres 

 de Lyon, Rhone; Avallon, Yonne; Se'mur, Cote-d'Or ; Salins, Jura; Pouilly-sous- 

 Charlieu, Loire ; Fontenay, Vendee, Moselle. 



In North Germany this species has been found at Orsleben and near Harzburg, at 

 Solenhai, near Leibenburg, and Falkenhagen, near Rischenau, and several other localities, 

 by Ewald, Strombeck, and Schlonbach. 



In South Germany very fine large specimens of this Ammonite, nearly identical with 

 the large examples found near Bath, are found in Wiirtemburg, Swabia, and Baden, and 

 are preserved in the Museums of Semur, Stuttgart, and Tubingen. 



In Austria it is found in the north-eastern Alps, associated with other leading fossils 

 appertaining to the same zone. La Spezzia, Tuscany (Pilla). 



In Luxembourg this species is collected from the " Gres de Luxembourg." 



I beg to refer the reader to the detailed sections I have given of the Bucklandi-beds 

 at Saltford (pp. 36 and 37), and at Broad Ledge on the shore of Lyme Regis (pp. 38 and 

 39), as the best examples I at present know of the stratigraphical position and relation 

 of this Life-horizon in the British Islands. 



In describing this Ammonite Mr. James Sowerby remarks : — " Found in the Blue Lias 

 of Bath and the neighbourhood, measuring from a foot to twenty-one inches or more in 

 diameter, and rather remarkable for having frequently lost the inner whorls ; which 

 circumstance, by a sort of friendly pun, has given rise to the name given to it in honour of 

 a meritorious and enlightened geologist, the Rev. W. Buckland, who, having found a 

 large specimen, was induced by his ardour to carry it himself, although of considerable 



