The books will tell you that these bats are distinguished by "complicated nasal appendages consisting of foliaceous skin processes around the nostrils," which is quite true and utterly futile.

The books suggest that these foliaceous appendages are the organs of some special sense akin to touch.

(B.) Polyzoarium foliaceous, calcareous, or horny, reticulate; cells only on one side.

Cells oval, not very regularly arranged, in a continuous, foliaceous, subcircular frond; reticulated with oval spaces, not as wide as the interspaces.