[[p. 316]] February 16th, 1873
The Dell,
Grays,
Essex.

"Dear Dr. Gunther,

     I wish now to ask you to be so good as to give me some advice and assistance in a work on geographical distribution I am now engaged on. I wish to give an accurate sketch of what is known of the distribution of each family, and where possible of each well marked and well established genus in the more important classes of land animals. For this purpose it is necessary to have the best existing classification and I shall be very much obliged to you if you can find time to note down for me the works in which I can obtain the best information on reptiles and amphibia.

     1st. As to the families and genera which are most natural and should be adopted. If no recent trustworthy work exists, perhaps you would kindly write out for me the series of families arranged in their respective groups and in the order in (which) they should most conveniently succeed each other.

     2nd. Indicate for me the works where I can get the best details of the genera and species and their distribution, for each order and each family.

     The families of extinct as well as living reptiles should be included.

     As to fishes I suppose if I work through your catalogues I shall have ample information for the mere sketch of these I can attempt.

     Of course I am aware how very imperfect and liable to error must be anything I can write from mere compilation on groups of which I am so ignorant as reptiles and fishes, but I only propose to give them in the more systematic part of the work, in order that it may not be incomplete, as I found my chief generalisations and arrange the general scheme of my book by a study of mammalia and birds, with the classification and distribution of which I am a little more familiar.

     If you can help me in the manner here indicated, I shall be very much obliged.

I remain,
Yours very truly,
Alfred R. Wallace."

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[[p. 317]] March 28th 1873
The Dell,
Grays,
Essex.

"Dear Dr. Gunther,

     I send you my tables of reptiles for you to look over as you kindly promised. I have added all the genera noticed in the 'Bericht' and 'Record' since the date of the catalogues of 'lizards' and 'snakes'. I have intercalated these as I could putting them as much as possible near genera from the same localities.

     As there are probably many genera which should be united in one genus, I think it would be convenient if you would indicate these by putting the same letter to them--a, a, a--b, b, b, b,--c, c,--etc. scoring under the name which should be retained for the appropriate genus. The genera and families which you consider to be most certainly natural can be indicated as you suggested by an asterisk (*).

     A few new families I have put in by guess. Please state which of the old families they had best come after.

     I had not time to add the new genera of tortoises--but as these are probably few, perhaps you will be so good as to insert those which you think are of any importance.

Believe me,
Yours very faithfully,
Alfred R. Wallace."