[The larval antennae in Lepas] correspond with the inferior antennæ, the superior2 being wanting, as in most Daphnidæ.3… I know of no case in which the inferior are obsolete when the superior are developed; but the reverse is often true.4
In CD’s copy of Living Cirripedia (1851): 15 n. (Cambridge University Library), ‘inferior’ and ‘superior’ are underlined in pencil. In the margin at the foot of the page CD noted: ‘p. 253. Annale. des Sc. M. Edwards Tom 16.— says 2d pair of antenni are the grand or external pair:’ (Milne-Edwards 1851, p. 253). At the top of the page CD wrote: ‘Lubbock thinks by inference that the superior in Calanidæ are the antica, or antenæ’. John Lubbock, in his first published paper, described a new species of Calanidae from CD’s Beagle collections (J. Lubbock 1853a, 1853b, and 1853c). He named this crustacean Labidocera darwinii (J. Lubbock 1853a). See also Hutchinson 1914, p. 33.
Daphnidae were ranked as a family of branchiopod crustaceans in the order Cladocera. In Baird 1850, p. 62, their antennae are considered to be a major character of the group: ‘Superior antennae generally very small; inferior large, almost always two-branched.’
CD’s view of the homologies of the larval antennae were diametrically opposed to Dana’s; he believed that in cirripedes the inferior larval antennae were rudimentary and the superior developed, and that the latter became in the second stage the prehensile antennae, or the means of attachment of the organism. See Living Cirripedia (1854): 105–6, and Correspondence vol. 5, letter to J. D. Dana, 8 May [1852].