The "ribs" are the same as the sides. Term term "ribs" is commonly used. Yes John means that the height of the "ribs" at the neck is 29mm and at the end pin 33mm.
The taper is done to enhance playability...to make the upper area of the neck more accessible so that the reach to the upper register is not to difficult. The violin in the photo below is 33mm at the end pin and 29mm at the neck.