TY  - BOOK
AU  - Cobban,William Aubrey
TI  - Scaphitoid cephalopods of the Colorado group: Evolution of Scaphites and related genera, with descriptions and illustrations of new species and a new genus from western interior United States
T2  - Geological Survey professional paper 239
AV  - QE75 .P9 no. 239
U1  - 564.53 
PY  - 1951///
CY  - Washington
PB  - U.S. Govt. Print. Off.
KW  - Ammonoidea
KW  - Scaphites
KW  - Paleontology
KW  - Cretaceous
N1  - "References": p. 39
ER  -