Order: Mesogastropoda <"middle stomach-footed">

(5-4-2-0-0-0-0-0-0-0-0-0-0)
Ref. Amer. Fish. Soc., 1988 p 58
Vaught, 1989 p 15
Syn. Ctenobranchiata
Ref. Keen, 1971 p 363