To Robert Fitch   1 February [1850]

Dear Sir

As this is the first of Feb^y. I write to report progress. I have lost 5 days by my own unwellness & the illness of one of my children.— On every other day, without exception I have worked 2$\frac{1}{2}$ hours (which the Doctors only allow me) on fossil Cirripedia. I believe I have now about 200 specimens in the house & the labour of comparing so many valves (many of which I have to clear out of matrix & repair) is great.

I have described eleven species in detail & next Wednesday I take up many specimens to be drawn.—¹ I suppose I have at least 12 more species to describe, of which several belong to you.—² I cannot work quicker, but I pledge myself to go steadily on with the fossil pedunculate species till they are finished.—

Please to observe that where there are many valves each species requires 5 or 6 pages of description.—

From the kindness of your notes, I do not believe you will object to my keeping your specimens somewhat longer—if I do not hear I shall understand I have your permission.—

Yours faithfully | C. Darwin

I forgot before to say that all your specimens shall be returned named specifically & with name of valve