A spicule with two rays; of or relating to structures with two radiating points.
From Greek dia- (two) + aktis (ray) + -ine (adjective/noun suffix). An alternative form emphasizing the two-rayed characteristic.
The same spicule might be called 'diact,' 'diactin,' or 'diactine' depending on which zoology textbook you read—scientific naming was messier before there were international standards!
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