Jetpack Tiled Gallery Grid captions

Does anyone know how to turn off the hover mode captions in the tiled gallery grids? Generally the text captions don’t fit if they are longer than about 3 words and they don’t wrap within the thumbnail areas either. I would rather just turn them off entirely. Also, CSS rules embedded in the theme’s style.css file don’t seem to override Jetpacks CSS?

.tiled-gallery-caption {
display: none;
}