Helix constricta Boubée, 1836 Trissexodon constrictus is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Trissexodontidae.

This species endemic to the western Pyrenees and the Basque Country across 29 recorded localities, being recorded in Spain (throughout the Basque Mountains) and in France (in the Department of Hautes Pyrénées to Department of Pyrénées-Atlantiques), (under records of the IUCN).

The umbilicus is deep and covers 1/7 of the shell diameter.

[4] Trissexodon constrictus is found under stones in the soil of humid and shady deciduous forests, between moss, under leaf litter and occasionally near cave openings.

It has been recorded from sea level to 800 m, and exceptionally to altitudes of 1500 m.[3][4] This article incorporates public domain text from the reference [4]