LETTER 261. TO E.S. MORSE. [Undated.

I must have the pleasure of thanking you for your kindness in sending me your essay on the Brachiopoda. (261/1. "The Brachiopoda, a Division of Annelida," "Amer. Assoc. Proc." Volume XIX., page 272, 1870, and "Annals and Mag. Nat. Hist." Volume VI., page 267, 1870.) I have just read it with the greatest interest, and you seem to me (though I am not a competent judge) to make out with remarkable clearness an extremely strong case. What a wonderful change it is to an old naturalist to have to look at these "shells" as "worms"; but, as you truly say, as far as external appearance is concerned, the case is not more wonderful than that of cirripedes. I have also been particularly interested by your remarks on the Geological Record, and on the lower and older forms in each great class not having been probably protected by calcareous valves or a shell.

P.S.--Your woodcut of Lingula is most skilfully introduced to compel one to see its likeness to an annelid.