Litorina or Littorina: How To spell?
The word Litorina is misspelled against Littorina, a noun meaning "A genus of small pectinibranch mollusks, having thick spiral shells, abundant between tides on nearly all rocky seacoasts. They feed on seaweeds. The common periwinkle is a well-known example. See Periwinkle."
Littorina has double "tt" is mispronounced as "t"Remember double 'TT' in between the strings li & orina which should not be misspelled with single 'T'
Wrong Spelling:  li-t-orina  Correct Spelling:  li-tt-orina 
Find more incorrect spellings of Littorina to spell right way.