|MadSci Network: Chemistry|
Sorry this took so long to answer, I have been out in the field scuba diving for sea snakes.
In answer to your question, the snake (land or sea) we most potent (drop for drop) venom is the inland taipan (Oxyuranus microlepidotus). For a complete list, go to the LD50 section of my database at: http://www.kingsnake.com/toxinology
All the best,
Try the links in the MadSci Library for more information on Chemistry.