A new species of Tretodictyum (Porifera: Hexactinellida: Tretodictyidae) from off Cocos Island, tropical eastern Pacific Ocean

A specimen of the genus Tretodictyum Schulze was found among the collections made by Harbor Branch Oceanographic Institute, Ltd., in their 1986 excursion to Cocos Island, tropical eastern Pacific Ocean. No member of that genus is known from the region. The specimen differs in many characters from the five known members of Tretodictyum and is described here as a new species, T. cocosensis.