Subject ASC0003tgi
The geological magazine, or, Monthly journal of geology.
Decade 3:v. 7 (1890), Page 343 (1890)
Smithsonian Libraries
BHL Page 30522325
Keywords
Graptolites H.O. Nicholson Didymograptus v-fractus Salter Skiddaw Slates Outerside Keswick polypari salter open graptolite