Thalasography or Thalassography: How To spell?
The word Thalasography is misspelled against Thalassography, a noun meaning "The study or science of the life of marine organisms."
Thalassography has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings thala & ography which should not be misspelled with single 'S'
Wrong Spelling:  thala-s-ography  Correct Spelling:  thala-ss-ography 
Find more incorrect spellings of Thalassography to spell right way.