408 AGOUTI. 
The Paca is more robust than the Agouti, with coarse hair, and 
no tail worth mentioning, and the inner toe and the nails on each 
foot very small. Like the Agouti, it is nocturnal, hiding in under- 
ground retreats in the forest by day, coming out at night to feed. 
It excavates burrows several feet deep, mostly in the vicinity of 
rivers. The subspecies mentioned below, with its parent species, 
and a smaller one, A. taczanowski, from Ecuador, are the only repre- 
sentatives of the genus known, the A. paca, however, having a wide 
distribution. A remarkable character in the Paca is the unusual 
development of the cheek bone, the malar being greatly inflated 
and excavated, and its outer surface roughened in an extraordinary 
degree. The cavity in the cheek bone is lined with a mucous mem- 
brane and communicates with the mouth by a small opening. The 
raison d’étre of this peculiar structure is unknown, and it can hardly 
be used as a pouch for food, like those of the Gophers and Chipmunks, 
for it would seem that any particles placed in this bony pouch would 
be apt to stay there, the animal having no means of extracting them. 
82. Agouti. Paca. 
I=; PMS; M2 
BS a = 
or) 
= 20. 
uv 
w 
Agouti Lacép., Tabl. Divis. Sous-divis. Ordres et Genres Mamm., 
Suppl. to Disc. d’ouvert et de cloture du Cours d’Hist. Nat., 
etc., 1799, p. 11. Type Mus paca Linneus. 
Coelogenus (sic) F. Cuv., Ann. du Mus., Hist. Nat. Paris, x, 1807, 
Pp: 203. 
Paca Fischer, Zoogn., 1814, p. 85. 
Osteopera Harlan, Faun. Amer., 1825, p. 126. ; 
Genyscelus Liais, Climats. Géol. Faune Brésil., 1872, p. 537. 
Five toes on hind feet; zygomatic arches greatly expanded verti- 
cally, forming bony capsules on side of face, communicating with 
mouth by a small opening at bottom of inclosed cavity. Head large 
and broad; nose not pointed; tail a fleshy tubercle; inner toes and 
the nail of each foot very small. 
paca virgata (Agoutt), Bangs, Bull. Mus. Comp. Zo6l., XXXIX, 1902, 
p. 47. 
CENTRAL AMERICAN Paca, 
Type locality, Divala, Chiriqui, Panama. 
Geogr. Disir. Central America. 
Genl. Char. Similar to the South American animal, but second 
stripes much less broken into spets; hind foot larger. Skull larger; 
palate narrower; audital bull flatter. 
