Pesulus or Pessulus: How To spell?
The word Pesulus is misspelled against Pessulus, a noun meaning "A delicate bar of cartilage connecting the dorsal and ventral extremities of the first pair of bronchial cartilages in the syrinx of birds."
Pessulus has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings pe & ulus which should not be misspelled with single 'S'
Wrong Spelling:  pe-s-ulus  Correct Spelling:  pe-ss-ulus 
Check more misspelled words of Pessulus to spell it correct.