THE APPLICATION OF DIDELPHIS MARSUPIALIS 
LINNAEUS. 
JAMES A. G. REHN. 
REcENTLy Dr. J. A. Allen published a paper, ** Note on the 
Generic Names Didelphis and Philander” (Bull. Amer. Mus. 
Nat. Hist., XIII, pp. 185—190), in which he takes exception to 
several statements recently published in this journal (XX XIV, 
pp. 575—577) by the present writer. A very hasty examination 
of Dr. Allen's paper convinced me that some of his conclusions 
must have been hastily formed, as they show a lack of detail. 
A more painstaking scrutiny has disclosed several interesting 
points in regard to the references cited by Linnaeus under his 
Didelphis marsupialis; as, like Dr. Allen, I have changed my 
views regarding the recognition of this name. 
To quote from Dr. Allen : **It is a recognized rule of nomen- 
clature that a name applied to a composite group, whether 
Specific or generic, must be conserved for some one of its 
components when the group is later subdivided.” With this I 
agree perfectly, and, as Dr. Allen argues, think we should give 
each reference cited under the name a close examination, the 
description being too indefinite to furnish anything. This Dr. 
Allen has done, but not as thoroughly as it should be. 
To take the references mentioned above, they are as follows : 
Philander Seb. Mus., I, p. 64, t. 39. 
Opossum Tyson, act., 290, p. 1565. 
Carigue Laét, Amer., 551. 
Carigueija brasiliensibus Marcgr. bras., 222; Pis. bras., 323; 
Jonst. quadr., 136, t. 36. 
Maritacaca Pis. bras., 323; Ray quadr., 182. 
Tlacuatzin Hernand, mex., 330. 
Concerning the first, the Philander of Seba, we find some- 
thing of interest even if it does not affect the whole. An 
147 
