252 Bulletin American Museum of Natural History. [Vol. XV I, 



he first describes at length the large Didelphis, or 'Tlaqatzin,' 

 of Mexico, with which he constantly compares the other forms 

 described with equal fulness later, showing that the Mexican 

 4 Tlaqatzin ' was the animal he ' had in his mind ' when de- 

 scribing mes-americana. Hence there seems to be no good 

 reason for not applying the usual rule to the present case and 

 restrict the name mes-americana to the large opossum of 

 'northern Mexico' ("nordl. Mexico"), since it long antedates 

 Bennett's and other later names for the same animal. 



(5) Did. boreo-americana (1. c., p. 1158). Relates exclu- 

 sively to the opossum of the eastern United States ("nur in 

 Virginien, Lusiana, Kanada"; also "im Lande der Illiner"). 

 Hence = Didelphis virginiana Kerr. 



The first intelligent account of the large opossums, based 

 on the comparison of considerable material, was published 

 by Temminck in 1825 (Mon. Mamm., 1825-1827, Deux. 

 Mon., 1825, pp. 27-35), who clearly distinguished three 

 species, and properly allocated their principal synonyms. 

 The first is his Didelphis virginiana, correctly characterized 

 and properly assigned to North America "depuis le Mexique 

 jusque dans les provinces septentrionales des Etats-Unis." 

 The second is his Didelphis azarcz, described from specimens 

 seen in European museums, and identified with the ' Micoure 

 premier, ou Micoure proprement dit' of Azara, and which he 

 says is found "au Bresil, ou il est tres-repandu," and, of 

 course, in Paraguay. His third species is Didelphis cancrivora, 

 which he identifies with "le Grand Philander oriental de 

 Seba, Thes. Vol. I, p. 64, tab. 38, fig. i [lege tab. 39];" he says 

 it is found over a great part of South America, but especially 

 in "le Guiane et le Bresil." It is Buffon's 'le Crabier,' which 

 he cites, as also Boddaert's and Gmelin's names based thereon; 

 but he makes no reference, under any of his species, to D. 

 marsupialis Linn. Yet in citing Seba, he cites the primary 

 basis, according to Thomas (cf. antea, p. 251, footnote), of 

 Linnaeus 's marsupialis. 



In his otherwise creditable notice of this group of opos- 

 sums Temminck makes the singular mistake of reversing the 

 colors of the ears of his D. azarce, which he says are yellow at 



