TY  - RPRT
TI  - The Mesozoic and Cenozoic Echinodermata of the United States
AU  - William Bullock Clark
AU  - Mayville William Twitchell
PY  - 1915
DO  - 10.3133/m54
UR  - https://pubs.usgs.gov/publication/m54
ID  - m54
ER  -