Source : Webster's Revised Unabridged Dictionary (1913)

Branchiogastropoda \Bran`chi*o*gas*trop"o*da\, n. pl. [NL., from
   Gr. ? gill + E. gastropoda.] (Zo["o]l.)
   Those Gastropoda that breathe by branchi[ae], including the
   Prosobranchiata and Opisthobranchiata.