Note 37 — 1. Family BALANIDÆ, (or Sessile Cirripedes). (continued 2)

The presence and absence of these cæca in genera so closely allied as Balanus and Tetraclita, shows, I think, that these cavities are not of high importance; and I must doubt whether Von Siebold’s view (‘Anatomie Comparée,’ tom. i, p. 445), that these cæca form a passage to a true or isolated liver, such as exists in the higher Crustacea, can be admitted. Cæca are said by Von Siebold to occur in some of the Entomostraca, as Daphnia, Argulus, &c.