The Collaborative International Dictionary
Siphonal
Siphonal \Si"phon*al\, a. Of or pertaining to a siphon; resembling a siphon.
Siphonal stomach (Zo["o]l.), a stomach which is tubular and bent back upon itself, like a siphon, as in the salmon.
Wiktionary
siphonal
a. (context zoology English) Resembling or relating to a siphon.