rhynchostome
/ˈrɪŋkə(ʊ)stəʊm/Zoology
noun
In whelks and related gastropods, and in nemerteans: the anterior opening of the rhynchodaeum, through which the proboscis is everted.
Origin
Late 19th century; earliest use found in Journal of the Royal Microscopical Society. From rhyncho- + -stome, after German Rhynchostom.