Mangelia umbrosa Melvill, 1923 Pilsbryspira umbrosa is a species of sea snail, a marine gastropod mollusk in the family Pseudomelatomidae.

(Original description) The small, narrow shell has a fusiform shape and is of rude sculpture.

It is dusky-brown with a rufous tinge over the body whorl and orifice.

The shell contains 7-8 whorls (the nepionic being imperfect in the specimens seen), the remainder longitudinally furnished with obtusely-rounded, strong, and frequent ribs, say about fourteen on the body whorl.

All the whorls are ventricose, impressed, and spirally plainly ridged suturally, and crossed by strongly developed spirals, swollen and almost becoming nodulous at the points of junction with the costae.