The collection entry says this is a seated female figure, but the label says male. Check out some more examples of Xochipilli on Google images.
Collected by William Bullock
“Jean-Henri Marlet03” by Jean-Henri Marlet (1770-1847) – http://www.dsloan.com/Auctions/A23/item-bullock-le_mexique-1824.html. Licensed under Public Domain via Wikimedia Commons.
Purchased by Rev Dr William Buckland
“William Buckland c1845” by Unknown. Licensed under Public Domain via Wikimedia Commons.
Excavated in Mexico
Currently displayed in Room 27, Ground Floor, British Museum
Acquired by the British Museum in 1825
Basalt? Volcanic stone
Height: 55 cm
Width: 32 cm
Two top images © Trustees of the British Museum
Let us know if you spot any clangers.