This site names several goddesses who guarded the canopic box.
http://72.14.205.104/search?q=cache:ClLsCySlAL4J:www.metmuseum.org/explore/newegypt/htm/rs_glos.htm+god+guard+canopic&hl=en&ct=clnk&cd=3&gl=us&ie=UTF-8
This site names four gods who guarded the contents of canopic jars.
http://en.wikipedia.org/wiki/Canopic_jar
the name of the god who guarded the canopic jar?
3 answers
http://www.touregypt.net/featurestories/animalgods.htm
Baboon y`n - The dog-headed baboon was one of the manifestations of both Thoth, god of writing, and Khonsu, the youthful moon god. Both deities were related to the moon. Hapy, the son of Horus who guarded the canopic jars that held the lungs, had the head of a baboon. There was also a baboon god in the Early Dynastic period named Hedjwer, 'The Great White One', who became closely linked with Thoth. Sometimes Thoth was shown in baboon form, perched on top of the scales of judgement in the underworld.
Baboon y`n - The dog-headed baboon was one of the manifestations of both Thoth, god of writing, and Khonsu, the youthful moon god. Both deities were related to the moon. Hapy, the son of Horus who guarded the canopic jars that held the lungs, had the head of a baboon. There was also a baboon god in the Early Dynastic period named Hedjwer, 'The Great White One', who became closely linked with Thoth. Sometimes Thoth was shown in baboon form, perched on top of the scales of judgement in the underworld.
Nephthys