\dor`si*bran`chi*a"ta\, n. pl. [NL., from L. dorsum back + branchiae gills.] (Zo["o]l.) A division of ch[ae]topod annelids in which the branchi[ae] are along the back, on each side, or on the parapodia. [See Illusts. under {Annelida} and {Ch[ae]topoda}.]