Bifide' is redundant in my opinion - it's simply a fancy word for 'double'. This goes without saying because they've also said that the 'évent' (blowhole) is double and the 'souffle' (spout/blow) is V-shaped.


Blow: a cloud or column of moist air forcefully expelled through the blowhole when the whale surfaces to breathe. For some species of whale this can be seen from many kilometers away. It is also sometimes referred to as a spout- which gives the mistaken impression that it is predominantly expelled water.

Blowhole: the modified nostril located on the top of a whale or dolphin's head. During dives the blowhole is sealed by a nasal plug which is retracted by fast-acting muscles upon surfacing for breathing. Baleen whales have two openings in their blowhole, while toothed whales have only one.
http://wwhandbook.iwc.int/en/downloadable-resources/glossary...

http://www.wordreference.com/fren/reverse/bifide