Solitary zooids: up to 120 mm long (Salpa thompsoni). Test strongly echinate. MI to MIII strongly fused in the mid-dorsal region; MVIII to MIX likewise strongly fused. Number of muscular fibers of MIV: 73-110.
Aggregate zooids: up to 60 mm long, excluding projections (Salpa thompsoni 1). Test thick and strongly echinate. Body muscles arranged as in Salpa fusiformis, but number of muscular fibers (MI-MVI): 140-235.