cirripedes

I must give one instance; he throws doubts and sneers at my saying that the ovigerous frena of cirripedes have been converted into branchiæ, because I have not found them to be branchiæ; whereas _he himself_ admits, before I wrote on cirripedes, without the least hesitation, that their organs are branchiæ.

Alfred Russel Wallace: Letters and Reminiscences, Vol. 1 James Marchant

I must give one instance; he throws doubts and sneers at my saying that the ovigerous frena of cirripedes have been converted into branchiae, because I have not found them to be branchiae; whereas he himself admits, before I wrote on cirripedes, without the least hesitation, that their organs are branchiae.

Alfred Russel Wallace Letters and Reminiscences Marchant, James 1916

If all pedunculated cirripedes had become extinct, and they have suffered far more extinction than have sessile cirripedes, who would ever have imagined that the branchiæ in this latter family had originally existed as organs for preventing the ova from being washed out of the sack?

VI. Difficulties of the Theory. Modes of Transition 1909

With species in a state of nature, every naturalist has in fact brought descent into his classification; for he includes in his lowest grade, that of species, the two sexes; and how enormously these sometimes differ in the most important characters, is known to every naturalist: scarcely a single fact can be predicated in common of the adult males and hermaphrodites of certain cirripedes, and yet no one dreams of separating them.

XIV. Mutual Affinities of Organic Beings: Morphology-Embryology-Rudimentary Organs. Classification 1909

Pedunculated cirripedes have two minute folds of skin, called by me the ovigerous frena, which serve, through the means of a sticky secretion, to retain the eggs until they are hatched within the sack.

VI. Difficulties of the Theory. Modes of Transition 1909

But that our rule is not confined to secondary sexual characters is clearly shown in the case of hermaphrodite cirripedes; I particularly attended to Mr. Waterhouse’s remark, whilst investigating this Order, and I am fully convinced that the rule almost always holds good.

V. Laws of Variation. A Part Developed in Any Species in an Extraordinary Degree or Manner, in Comparison with the Same Part in Allied Species, Tends to Be Highly Variable 1909

Still more recently, a Pyrgoma, a member of a distinct subfamily of sessile cirripedes, has been discovered by Mr. Woodward in the upper chalk; so that we now have abundant evidence of the existence of this group of animals during the secondary period.

X. On the Imperfection of the Geological Record. On the Sudden Appearance of Whole Groups of Allied Species 1909

This is the case with the male Ibla, and in a truly extraordinary manner with the Proteolepas: for the carapace in all other cirripedes consists of the three highly-important anterior segments of the head enormously developed, and furnished with great nerves and muscles; but in the parasitic and protected Proteolepas, the whole anterior part of the head is reduced to the merest rudiment attached to the bases of the prehensile antennæ.

V. Laws of Variation. Compensation and Economy of Growth 1909

For instance, the several species of the Chthamalinæ (a sub-family of sessile cirripedes) coat the rocks all over the world in infinite numbers: they are all strictly littoral, with the exception of a single Mediterranean species, which inhabits deep water, and this has been found fossil in Sicily, whereas not one other species has hitherto been found in any tertiary formation: yet it is known that the genus Chthamalus existed during the Chalk period.

X. On the Imperfection of the Geological Record. On the Poorness of Palaontological Collections 1909

I can only thus understand a fact with which I was much struck when examining cirripedes, and of which many analogous instances could be given: namely, that when a cirripede is parasitic within another cirripede and is thus protected, it loses more or less completely its own shell or carapace.

V. Laws of Variation. Compensation and Economy of Growth 1909