A LIST OF THE GENERA AND FAMILIES OF MAMMALS. 23 
Rodents, Marsupials, ete. Some have been described with considerable 
detail, and it is interesting to note that in one or two instances extinct 
forms have actually been found possessing the characters assigned. 
The hypothetical genera thus far proposed are brought together in the 
following list: 
LIST OF HYPOTHETICAL GENERA. 
Aligon Haeckel, 1895, Ungulata. Patrotherium  Haeckel, 1895, Monotre- 
Anthropomorphus Ameghino, 1889, Pri- ^ mata. 
mates. Peragonium Haeckel, 1895, Marsupialia. 
Archibradys Haeckel, 1895, Edentata. Pestypotherium Haeckel, 1895, Ungulata. 
Archididelphys Haeckel, 1895, Marsup. | Pithecanthropus Haeckel, 1866, Primates. 
Archilagus Haeckel, 1895, Glires. Proanthropomorphus Ameghino, 1889, 
Archimanis Haeckel, 1895, Edentata. Primates. 
Archipatagus Haeckel, 1895, Chiroptera. | Procarnassium Haeckel, 1895, Carnivora. 
Archipithecus Haeckel, 1895, Primates. | Prolagopsis Forsyth Major, 1899, Glires. 
Archiprimas Haeckel, 1895, Primates. Prophalangista Haeckel, 1895, Marsupi- 
Architherium Haeckel, 1895, Monotre- alia. 
mata. Protosirena Haeckel, 1895, Sirenia. 
Architrogon Haeckel, 1895, Glires. | Protanthropus Haeckel, 1895, Primates. 
Archorycterus Haeckel, 1895, Edentata. Protechidna Haeckel, 1895, Monotremata. 
Archungulatum Haeckel, 1895, Ungulata. | Prothomo Ameghino, 1889, Primates. 
Bunotherium Cope, 1874, Ungulata. | Prothylobates Ameghino, 1889, Primates. 
Choriotherium Haeckel, 1895 i | Protobalaena Haeckel, 1895, Cete. 
Collensternum Ameghino, 1889, Primates. | Protodelphinus Haeckel, 1895, Cete. 
Coristernum Ameghino, 1889, Primates. | Protosimia Ameghino, 1889, Primates. 
Diprothomo Ameghino, 1889, Primates. | Protroglodytes Ameghino, 1889, Primates. 
Diprotosimia Ameghino, 1889, Primates. | Tetraprothomo Ameghino, 1889, Pri- 
Diprotroglodytes Ameghino; 1889, Pri- mates. 
mates. |! Triprothomo Ameghino, 1889, Primates. 
Eutypotherium Haeckel, 1895, Typo- | Triprotosimia Ameghino, 1889, Primates. 
theria. Triprotroglodytes Ameghino, 1889, Pri- 
Hinnulus Ogilby, 1837, Ungulata. mates. 
Hippops Marsh, 1892, Ungulata. Tritomodon Cope, 1882, Marsupialia. 

Palahyrax Haeckel, 1895, Ungulata. | 
CHANGES IN FORM OF NAMES. 
EMENDATIONS. 
Probably no section of the A. O. U. Code has been the subject of so 
much criticism as Canon XL, which provides that *'the original 
orthography of a name is to be rigidly preserved, unless a typograph- 
ical error is evident." ^ Stability and priority are two of the cardinal 
principles under the Code, but priority is merely a means of securing 
stability, and applies as well to the adoption of the earliest name as 
to the earliest form of that name. Experience has shown that any 



&See Elliot, ‘Canon XL, A. O. U. code,’ Auk, XV, 294-298, 1898, and Allen, ‘A 
defense of Canon XL of the A. O. U. code,’ ibid., pp. 298-303. On emendation of 
names, see also Gill, Proc. Am. Ass. Adv. Sci., XLV, 1896, sep., pp. 9-10; Sclater, 
Proc. Zool. Soc. London, 1896, 313; Stebbing, Zoologist, 1898, 423-428. 
