Stejneger discussed the various aspects of this problem (_op. cit._, pp. 6, 7), and I can add nothing to his discussion. His arguments for the acceptance of Fitzinger's type designation rather than that of Geoffroy are well founded upon the statement of the International Rules of Zoölogical Nomenclature, while those of Smith are not. In weighing these two alternatives, the practical value of maintenance of the "status quo" is not here important, for the whole system of nomenclature in this field is completely upset; _any_ conclusive decision would be of great practical value and one alternative holds no special, practical advantage over the other. Accordingly, it seems reasonable to consider the matter closed with Stejneger's analysis, retaining _Amyda_ for the American and related species of soft-shelled turtles. That this assemblage contains natural subgroups that may warrant subdivision into other genera is obvious, but to none of these will the name _Trionyx_ be applicable. Table of Data on _Amyda_ Transcriber's note: Legend has been created for the column headings to make the table fit. Column headings: A: Number B: Sex (M = male, F. = female) C: Width (mm.) D: Length (mm.) E: Ratio, width-length F: Height (mm.) G: Ratio, width-height H: Neurals I: Costals ================+==========+===+=====+=====+======+====+======+===+===== SPECIES | A | B | C | D | E | F | G | H | I ----------------+----------+---+-----+-----+------+----+------+---+----- _emoryi_ | 2219[A] | | 81 | 62 | 1.30 | 34 | 2.38 | | 7 " | 2215 | M | | | | | | 7 | 7 " | 2216 | | 104 | 88 | 1.18 | 18 | 5.77 | 8 | 7 " | 2217 | | | | | | | 7 | 8 " | 2218 | | 106 | 93 | 1.14 | 21 | 5.04 | 7 | 7 " | 2803 | F | 150 | 132 | 1.13 | 28 | 5.35 | 7 | 7 " | 2824 | F | 204 | 198 | 1.03 | 32 | 6.37 | 7 | 7 " | 2837 | F | | | | | | 7 | 7 " | 19460 | | 97 | 77 | 1.26 | 14 | 6.93 | 8 | 7 | | | | | | | | | _ferox mutica_ | 16528 | F | 282 | 295 | 0.99 | 53 | 5.32| 7 | 7 " | 2841 | F | 99 | 75 | 1.32 | 16 | 6.18 | 7 | 7 " | 23230[A] | | 101 | 78 | 1.29 | 55 | 1.83 | 7 | 7 " | 2838 | F | 106 | 79 | 1.34 | 17 | 6.23 | 7 | 7 " | 1964 | M | 110 | 95 | 1.15 | 18 | 6.11 | 7 | 7 " | 2839 | F | 115 | 77 | 1.49 | 18 | 6.39 | 7 | 7 " | 2840 | F | 115 | 85 | 1.35 | 17 | 6.76 | 8 | 7-8 " | 19459 | | 131 | 106 | 1.23 | 20 | 6.55 | 7 | 7 " | 2220 | F | 144 | 116 | 1.24 | 22 | 6.54 | 7 | 7 " | 1874 | | 162 | 137 | 1.18 | 32 | 5.06 | 7 | 7 " | 1930 | F | 180 | 138 | 1.30 | 33 | 5.45 | 8 | 7