Mechanics: Plural possessive of a family name

The New York Times report of a well-known British conductor’s assisted suicide alongside his wife has a passage that illustrates a rare and tricky challenge.

The conductor was Sir Edward Downes, and his wife was Lady Downes. The story never uses the expected plural of Downes: Downeses. (The rule is for a noun ending in -s, add -es to make the plural form.) The story seems to avoid the plural, referring to the Downes family.

However, John F. Burns’ account contains this passage:

But British news reports about the Downes

This article was originally posted by the Raleigh News & Observer, a subsidiary of The McClatchy Co.; is posted here to provide continuity; and is copyright © 2011 The News & Observer Publishing Company, which reserves the right to remove this post.