Why was 'Alice's Adventures in Wonderland' banned?

It is difficult to find information on the banning of Alice's Adventures in Wonderland.

Banned Books Week: September 25--October 2. University of California, San Diego Social Sciences & Humanities Library website says:

Alice's Adventures in Wonderland

Lewis Carroll

1900

Suspended from classroom use, pending review, at the Woodsville High School in Haverhill, New Hampshire, because the novel contains expletives, references to masturbation and sexual fantasies, and derogatory characterizations of a teachers and of religious ceremonies.

1931

Banned by the Chinese Governor of Hunan Province on the ground that "Animals should not use human language, and that it was disastrous to put animals and human beings on the same level."

However, as they don't provide a source for this information, it is impossible to verify. (See Related Link below)

The File Room, a website dedicated to the cataloging of bannedliterature, repeats the claim about the book being banned in Hunan Province and cites its source as Banned Books 387 B.C. to 1978 A.D., by Anne Lyon Haight, and Chandler B. Grannis, R.R. Bowker Co, 1978. (See Related Link below) This appears to be the origin of claims that the book was banned in China, but corroborative evidence remains elusive.