My dear Sir

In a weeks time I hope to send to you two volumes on the Fossil & Recent Lepadidæ.¹ If you have time & inclination, I shall be delighted if you will look at the latter, more especially at the sexual relations of Ibla & Scalpellum. I hardly expect to be believed on this latter head, though I am well convinced of the truth of my statements, for I honestly & carefully & repeatedly went & rewent over my dissections.—²

With the two vols. I send a Crustacean, taken by Capt. Sulivan³ R.N. out of a Dolphin’s stomach amongst the Gulf Weed:⁴ I have almost forgotten the very little I ever knew about the Crustacea; but this seems to me a very curious form, & therefore I shall be much pleased if it turns out worthy of your acceptance & description. When I first saw it much shrunk, I actually thought it was the larva of some Homopterous insect!! I call your attention to some fragments, (as I suspect), adhering to the legs, of the curled horns on the carapace; this, however, may be a mistake, as I did not choose to disturb them.

I have examined the Sporillus, which you so very kindly sent me:⁵ it is a very curious species of Acasta, & cannot be separated from that genus: I have from Sumatra a distantly allied form embedded in the bark of an Isis:⁶ I have no doubt your specimens had been originally imbedded in some analogous production;⁷ for they had long lain dead, & carbonate of lime had been deposited on their insides. Do you remember did you dredge up at same time any such corticiferous coral. &c.?— Have you published any name: in my M.S. I have called it, Acasta sporillus: do you object to this, supposing no name yet published? I presume I may state that I owe the specimens to you.?⁸

And now I am going to beg you to do me a great favour, namely, as far as you can, to give me the names & geographical distribution, of three or four sma⁠⟨⁠ll⁠⟩⁠ pieces of coral (not to be returne⁠⟨⁠d)⁠⟩⁠ in which cirripedes were imbedded. I can only spare small fragments, but I have taken care that they resemble the whole pieces in my possession. I have no habitats for the cirripedes in question, & thus hope for the chance (& I know it is a chance) of asertaining their habitats with more or less certainty by that of the corals.⁹ I am very anxious on this head.— I trust that you will forgive this trouble.

Pray believe me, with my best hopes that you are well & prosperous, Yours with much respect, very sincerely | C. Darwin

The corals shall be numbered & so you can easily refer to them in your answer.—