Mammals from Sujuy. 195 
16. Dasyprocta variegata bolivie, Thos. 
Immature skull. ¢. Villa Carolina. 500 m. 
17. Galea comes, Thos. 
3S. 635, 666, 670, 691, 708; 9. 643, 657, 661, 664, 696, 
700, 701. Villa Carolina. 1258 m. 
18. Sylvilagus brasiliensis gibsont, Thos. 
3. 690. Villa Carolina. 500 m. 
Not fully adult. Nape-patch less rufous than in type. 
19. Marmosa * budini, sp. n. 
3.714. Altura de Yuto, Rio San Francisco. Alt. 
500 m. 
“ Caught in an upland wood.”—E£. B. 
: A medium-sized species, grey above and buffy yellowish 
elow. 
* Tam quite unable to accept the nomenclatural results of Dr. Matschie’s 
recent paper on the Didelphiidss (SB. Ges. Nat. Fr. Berl. 1916, p. 259). 
because, as in other cases, he bases his whole work on the obsolete and 
now generally discarded principle of elimination, instead of using modein 
methods for the identification and selection of genotypes. Some of his 
conclusions in the present case would be specially unacceptable to workers 
in general, such as his entire ignoring of my selection in 1888 of brachy- 
urus as the type of Peramys, Less., and his long and complicated argu- 
ments that because the other species of the original Peramys—brachyurus, 
tristriata, and pusidla—fall into other genera, the fourth species men- 
tioned—crassicaudata—must be taken as the genotype. Such a definite 
selection of the genotype of Peramys (brachywa) as that in the ‘ Catalogue 
of Marsupials’ is in accordance with modern usage and cannot be ignored. 
With regard, however, to Monedelphis, Burm., although Dr. Matschie’s 
selection of its genotype is obtained, as I consider, in the wrong way, yet 
he has made a selection, and, in the absence of an earlier one, that would 
be valid, and I would therefore accept “‘ brachyura” as its genotype. In 
consequence Monodelphis would antedate and supersede Peramys for the 
genus containing the common short-tailed opossum. 
All Dr, Matschie’s recent nomenclature work is similarly based on this 
unsound principle of elimination, so that his exceptional literary know- 
ledge is rendered nugatory so far as the utilization of his results is 
concerned. 
Incidentally I may note that the group called Micoureus by Matschie, 
who quotes its type as D. laniger, Desm., appears to need a new name, as 
Micoureus, Lesson, with type by subsequent selection D. cinerea (Thomas, 
1888), properly goes to quite a different group. I would suggest the 
name Mallodelphys for the former, with D. laniger as its genotype. It 
should, I think, rank as a subgenus of the genus Philander, whose geno- 
type, by tautonymy, is Philander philander, L. 
