1902.] Allen, Opossu?ns of the Genus Didelphis. 251 



not convinced that Seba's animal (pi. xxxix) was identifiable 

 a reexamination of the case leads me to accept Mr. Thomas's 

 conclusion. 1 



The Didelphis marsupialis case being settled, the next 

 names in order of time for the South American large opos- 

 sums are D. karkinophaga Zimmermann, 1780, D.carcinophaga 

 Boddaert, 1784, and D. cancrivora Gmelin, 1788, all of which 

 were based on Buffon's 'le Crabier' from Cayenne, and are 

 therefore all synonyms of D. marsupialis as now restricted. 

 Next in order of date are Oken's names for the large opossums 

 of both North and South America, of which he recognized five 

 species, giving new names to four of them, as follows: 



(1) Did[elphys] cancrivora (Lehrbuch der Naturgeschichte, 

 Theil III, Abt. ii, 1816, p. 1146). Based on Buffon's 'leCra- 

 bire,' and hence = Didelphis cancrivora Gmelin. 



(2) Did. paraguayensis (L c., p. 1147). Based primarily on 

 the ' Micoure' premier ' of Azara, with which he correctly asso- 

 ciates the ' Tai-ibi Brasiliensibus ' of Marcgrave. = Didelphis 

 azarcB Temminck, 1825. 



(3) Did. austro-americana (1. c., p. 1148). Relates mainly 

 to the large South American opossums of the Didelphis 

 group, but also includes references to species of Metachirus 

 and Caluromys. = Didelphis marsupialis Linn, mainly. 



(4) Did. mes-americana (1. c., p. 1152). Relates primarily 

 to the Mexican ' Tlaqatzin,' or to the " Tlaqatzin in Neu Span- 

 ien (nordl. Mexico), auch in andern Gegenden Amerikas unter 

 verschiedenen Namen." These other names and regions in- 

 clude the " Qarigueya an der Kiiste von Brasilien, Jupatiima im 

 Innern, Taibi in Paraguay," etc., of South America, and the 

 'Manicu' of the lesser Antilles, with references also to Florida 

 and Darien. Although D. mes-americana is thus composite, 



1 Mr. Thomas says (Ann. and Mag. Nat. Hist. (7) VIII, Aug. 1901, p. 153): "The 

 evidence of the sixth edition of the 'Systema,' where Seba, and Seba only, is quoted, 

 shows what animal Linnaeus had in his mind when speaking of marsupialis." This 

 statement can hardly be taken strictly, as in the sixth edition (p. 10), Linnaeus did 

 not use the name marsupialis, but simply Didelphis, of which he recognized two groups 

 (species?), namely, "i. Didelphis mammis intra abdomen," and "2. Didelphis 

 mammis extra abdomen," citing Seba only under each. Under the first he gives "Seb. 

 thes. I, t. 36, f. i, 2 & t. 39." The first plate reference here cited later became the 

 exclusive basis of Linnaeus' s Didelphis opossum (cf. Thomas, Cat. Marsup. and Monotr., 

 1888, p. 329), while the other became in part the basis of his D. marsupialis. He 

 thus, in the tenth edition, made two species of his No. i of the sixth edition, citing 

 of Seba's plates only pi. 'xxxix under his D. marsupialis, and in so doing restricted his 

 marsupialis, so far as Seba is concerned, to pi. xxxix. 



