106 
JOURNAL OF MAMMALOGY 
ON THE ‘‘HABITUS’^ AND HERITAGE^’ OF C-^NOLESTES 
By William K. Gregory 
The more closely one studies Dr. W. H. Osgood^s excellent monograph 
on Ccenolestes^ the more one must be grateful to him for the quality and 
range of his plates, for the thoroughness of his comparisons (within 
the limits of available material) and for his eminently fair and impartial 
presentation and analysis of the difficult subject of the precise relation- 
ships of that animal to other marsupials. Doctor Osgood’s monograph 
has already been reviewed in a recent number of this journaP and I 
have no wish to offer detailed criticisms or to challenge the author’s 
main conclusions. But a careful study of this work and of Lonnberg’s 
recent brief paper^ has resulted in the following preliminary and partial 
analysis, in which an attempt is made, first, to bring out the correlation 
of habit and structure, and secondly, to make a beginning towards 
separating those features which have been acquired during the present 
life habits (habitus) from those which have been inherited from previous 
life habits (heritage).^ Unless otherwise noted the statements of 
anatomical fact are to be credited to Osgood. 
I. LIFE HABITS AND ECOLOGY 
1. Geographic Distribution. Present: Andes of Venezuela, Colombia, 
Ecuador, Peru. Past: Ccenolestes is a survivor of the Santa Cruz 
Miocene Epanorthidie (Palseothentidse) of Patagonia. 
2. Life Zone. Cool, dense forests at high altitude, 6 to 12 thousand 
feet, near timber line. Also in grassy openings of mountain vallej^s. 
Ccenolestes lives in dense growth, beneath the canopy of the tree tops 
and still further shaded by masses of low vegetation. Osgood infers 
that ‘it is crepuscular or nocturnal in habits. Found in runways among 
the thick grass in swampy ground, about on a level with the water line 
of the swamp. Lonnberg (1921) says it is arboreal in habits, but this 
seems doubtful. 
1 A Monographic Study of the American Marsupial, Cosnolestes. Field Mus. 
Nat. Hist., Zool. Ser., vol. 14, no. 1, pp. 1-162, May, 1921. 
2 Journ. Mammal., vol. 2, no. 4, pp. 241, Nov., 1921. 
3 A Second Contribution to the Mammalogy of Ecuador, with some remarks on 
Ccenolestes. Arkiv. f. Zool., Bd. 14, no. 4, pp. 1-104, 1921. 
^ Gregory, 1913. Locomotive Adaptations in Fishes, Illustrating “Habitus” 
and “Heritage.” Ann. N. Y. Acad. Sci., pp. 267-268; Osborn, 1917. Heritage 
and Habitus, Science, N. S., vol. xlv, no. 1174, pp. 560-561. 
