What is "hirundo horreorum"

Barn \Barn\ (b[aum]rn), n. [OE. bern, AS. berern, bern; bere barley + ern, [ae]rn, a close place. [root]92. See Barley.] A covered building used chiefly for storing grain, hay, and other productions of a farm. In the United States a part of the barn is often used for stables.

Barn owl (Zo["o]l.), an owl of Europe and America ( Aluco flammeus, or Strix flammea), which frequents barns and other buildings.

Barn swallow (Zo["o]l.), the common American swallow ( Hirundo horreorum), which attaches its nest of mud to the beams and rafters of barns.