Requests information on ranges of echinoderms for his essay on variation [Natural selection]. Are there genera with representative species in northern and southern seas, but none in tropics?
Down Bromley Kent
My dear Gray
You once told me that you would help me in my Essay on variation. I want much some information on a point of Geographical Distrib., & to be allowed, to give information on your authority. It is, whether there are genera of Echinoderms, starfish &c, which have species (especially if closely related) in the Northern & Southern seas, but have not any one species in the Tropical seas? Or whether there are any closely related & representative genera in the north & south, without any closely related genus within the Tropics?
I am quite ignorant about the range of Echinoderms & perhaps all the genera have very confined ranges. Could I find information on this head in any publication?
Pray forgive, if you can, the trouble, & believe me, Yours very sincerely | Ch. Darwin
- f1 1915.f1The year is suggested by CD's interest in the distribution of marine animals (see letter to T. H. Huxley, 1 July .).
- f2 1915.f2Gray is not listed among the authorities cited in the section of Natural selection devoted to the distribution of marine animals in the polar and tropical seas (pp. 555–7).