628 Bulletin American Museum of Natural History. [Vol. XXXIV, 
Five specimens are referred to this form, representing the following localities, 
all in the tropical coast zone of western Colombia: Los Cisneros, 2; Rio Osculo, 
Baudo, and Bagado, each 1. The Bagado specimen is not typical, it differing from 
the others in having the top of the head and back of the neck to the shoulders very 
much darker than the others, but is otherwise similar. 
This form is related on the one hand to subspecies zamore, as noted 
above, and on the other to subspecies colombiana. Indeed, in the large 
series of the latter from near Bonda (Santa Marta district), are specimens 
closely similar to some of the Chocé specimens, but the two series as a whole 
present well-marked color differences, colombiana being grayer, the annu- 
lations of the hair tips paler and narrower, the white tips of the hairs of the 
rump shorter, with a tendency to a conspicuous blackish area on the back 
anterior to the rump, which latter feature is absent in chocoensts and zamore. 
The skulls, however, show that colombiana is a much larger animal than 
either gamore or chocoensis, with a broader and much more massive skull. 
Two half-grown specimens from Frijolera, Antioquia, closely resemble 
specimens of similar age from Santa Marta, and are here provisionally 
referred to colombiana. | 
D. ». chocoensis is not closely related to D. isthmica, the latter being 
paler with the long light tips to the hairs of the rump distinctly yellowish 
instead of white. So far as coloration is concerned, D. isthmica presents a 
striking similarity to D. aurea of the far away region of southern Matto 
Grosso. 
Note on the Orange-rumped Agoutis. 
The earliest available names for the orange-rumped agoutis appear to 
be Dasyprocta croconota Wagler for the Amazonian form and D. prymnolopha 
Wagler! for the Guiana form. No definite type locality was given for 
either, but D. croconota was based on a specimen collected by Spix on the 
Amazon, and D. prymnolopha on specimens from Guiana. Two specimens 
in the American Museum collected by Leo E. Miller (Roosevelt Brazilian 
Expedition) at Calama, on the lower Rio Madeira, agree satisfactorily with 
Wagler’s description of his D. croconota.2 As Spix spent a long time on the 
Amazon near its junction with the Rio Madeira and Rio Negro, and ascended 
the lower parts of both of these rivers, it seems not unreasonable to indicate 
| Dasyprocta croconota Wagler, Isis, 1831, p. 618. ‘’Brasilia ad flumen Amazonum.”’ 
From Spix’s Expedition. 
Dasyprocta prymnolopha Wagler, cbid., p. 619. ‘‘Habitat in Guiana.” 
2 Except that the incisors are not white. It is probable that the ascribed ‘‘dentibus pri- 
moribus toto niveis’’ is an exceptional condition.. In over 100 Dasyprocta skulls now before 
me, not one has the incisors all white, but in three or four they are pale yellowish white, or 
mottled with pale yellow and white, giving a whitish general effect. 
