Journ. Anat. Phys. Paris, xxi. 1885.
Fauna and Flora G. v. Neapel, Monogr. x. 1884.
These sphincters close the only openings through the tough test so effectually that when collectors are preserving Ascidians in alcohol it is advisable to make one or more slits in the test to allow the sea-water to escape and the spirit to enter.
Except in Cynthiidae and Botryllidae where it is dorsal.
The early stages of Ciona, of which Castle has given a very complete account (Bull. Mus. Comp. Zool. xxvii. No. 7, 1896), differ in some points from those of Ascidia described here.