Nolcx on Ricfimoiid and R laird Fonsils 55 



Bird's-hill, north of Llaiulilo, in southern Wales. 

 Figures, 8 3a, 3b, 4, ^a are reproductions of the origi- 

 nal figures accompanying the description of Orthis 

 retrorsa, l\y Salter, in the Memoirs of the Geolog- 

 ical Survey of Great Britain, vol. "2, ]>t. 1, on plate 

 XXVII, and retain the original numbering. 



Pig. 5. Zitteloceras hallianum, D'Orbigny. A, lateral view; 

 15, ventral view, enlarged 2.(' diameters. Type, 

 numbered 8'-23, in the American Museum of Natural 

 History, in New York City. From the Trenton 

 limestone, at Middleville, New York. 



