Penatulacea or Pennatulacea: How To spell?
The word Penatulacea is misspelled against Pennatulacea, a noun meaning "A division of alcyonoid corals, including the seapens and related kinds. They are able to move about by means of the hollow muscular peduncle, which also serves to support them upright in the mud. See Pennatula, and Illust. under Alcyonaria."
Pennatulacea has double "nn" is mispronounced as "n"Remember double 'NN' in between the strings pe & atulacea which should not be misspelled with single 'N'
Wrong Spelling:  pe-n-atulacea  Correct Spelling:  pe-nn-atulacea 
Check more misspelled words of Pennatulacea to spell it correct.