Chapter Tumbledung to Tunicata of T by Webster's Dictionary (1913 Edition)

of water. The pharynx is usually dilated in the form of a sac, pierced by several series of ciliated slits, and serves as a gill.

Most of the species when mature are firmly attached to foreign substances, but have free-swimming larvæ which are furnished with an elongated tail and somewhat resemble a tadpole. In this state the larva has a urochord and certain other structures resembling some embryonic vertebrates. See Ascidian, Doliolum, Salpa, Urochord, and Illust. of Social ascidian, under Social.