Author (if known) last name, first name. Name of the Site. Publisher, Date of publication, URL (Location).
When there is no known author or editor:
Author (if known) last name, first name. "Title of the Page or Section." Title of Website, Name of the institution associated with the site, Date of publication, URL (Location).
Note: If the author's name and publisher's name are the same, use it in place of the publisher's name and begin the work cited entry with the title of the source. The 8th edition no longer requires a City of Publication. The URL is optional, and you should always consult your instructor's preferences before including it.
This example is similar to the one in section 5.33 on page 136 of the MLA Handbook, 9th Edition.
If you're citing the short story, "The Masque of the Red Death" by Edgar Allen Poe which is in volume 4 of a multi-volume edition of his complete works that was published in 1902 and is available via the HathiTrust Digital Library, then that citation would look like this: