Edition of 1905.  See also Sea cucumber and Ascidiacea on Wikipedia, and the disclaimer.

SEA-SQUIRT. Any of several marine animals which have the power of ejecting water when removed from their native element. In the West Indies the large holothurians (q.v.) which eject water from the respiratory trees through the anal opening are often so called. The name is more commonly and rather more properly applied to the larger ascidians (q.v.), which force the water out of the atrial cavity through the atrial pore by the contraction of the tunic, often with considerable velocity, and for many inches.