In animal anatomy, Henry's pocket, more formally known as a cutaneous marginal pouch, is a fold of skin forming an open pouch on the lower posterior part of the

external ear The outer ear, external ear, or auris externa is the external part of the ear, which consists of the auricle (also pinna) and the ear canal. It gathers sound energy and focuses it on the eardrum (tympanic membrane). Structure Auricle The ...

. The pocket is situated in the approximate location of the

antitragus The antitragus is a feature of mammalian ear anatomy. In humans, it is a small tubercle on the visible part of the ear, the pinna. The antitragus is located just above the earlobe and points anteriorly. It is separated from the tragus by the ...

in the human ear. It occurs in a number of species, including

weasel Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets and European mink. Members of this genus are small, active predators, with long and slender b ...

s and

bat Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most ...

s, but is particularly noticeable on the domestic cat, as well as some dog breeds. The pocket is of unknown function, and it is unclear if it has any at all. However, one hypothesis is that it aids in the detection of high-pitched sounds by attenuating lower pitches, especially when the ear is angled, common for a predator when hunting. Since the pocket occurs in a wide variety of mammalian species, it is likely a conserved feature from their common ancestor. The pocket is a common area for

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

s to gather, and should be checked during a veterinary examination.

References

Animal anatomy {{vertebrate-anatomy-stub