My dear Sir

I have seldom been more deeply gratified, than by receiving your most kind present of “Lake Superior”: I had heard of it, & had much wished to read it, but I confess that it was the very great honour of having in my possession a work with your autograph, as a presentation copy, that has given me such lively & sincere pleasure. I cordially thank you for it. I have began to read it with uncommon interest, which I see will increase as I go on.—¹

The Cirripedia which you & D^r. Gould were so good as to send me,² have proved of great service to me. The sessile species from Massachussets consist of five species; I will give their names &c, though I do not know whether you will care to hear about them.—

1) Balanus balanoides ³ = Lepas balanoides Linn (= B. punctatus of most British authors)—a littoral species; Europæan. B. ovularis & elongatus of D^r. Goulds named specimens—

(2) B. vulgaris (?) = L. balanoides Linn. (confounded by most or all authors with B. balanoides) Europæan deepish water. B. rugosus & Balanoides of D^r Gould’s named specimens.

3) B. sulcatus Brugiere = L. balanus Linn. = B. geniculatus Conrad Europæan

4. B. tulipa Müller = B. candidus & scoticus of British authors, (sent mingled with B. eburneus by D^r Gould.) Europæan

5. B. eburneus Gould. —— United States.—

Of the genus Balanus on the shores of Britain we have one species B. perforatus Brugière⁴ which you have not in U. States; in the same way as you exclusively have B. eburneus.—

All the above species attain a somewhat larger average size on the shores of the U. States than on those of Britain, but, the specimens from the Glacial beds of Uddevalla, Scotland & Canada are larger even than those of the U. States.

If you think that D^r. Gould would care to see these few remarks on the Cirripedia of the U. States, will you kindly send him this letter.

I have not yet examined the Chthamalus & Chelonobia you sent me from Charlestown.—⁵

Once again allow me to thank you with cordiality for the pleasure you have given me

Believe me with the highest respect | Yours truly obliged | C. Darwin