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'etre 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. 



Agouti Lacep., Tabl. Divis. Sous-divis. Ordres et Genres Mamm., 

 Suppl. to Disc, d'ouvert et de cloture du Cours d'Hist. Nat., 

 etc., 1799, p. ii. Type Mus paca Linnaeus. 



Coelogenus (sic) F. Cuv., Ann. du Mus., Hist. Nat. Paris, x, 1807, 

 p. 203. 



Paca Fischer, Zoogn., 1814, p. 85. 



Osteopera Harlan, Faun. Amer., 1825, p. 126. 



Genysccelns Liais, Climats. Geol. Faune Bre'sil., 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 (Agouti}, Bangs. Bull. Mus. Comp. Zool.,xxxix, 1902, 



P- 47- 

 CENTRAL AMERICAN PACA. 



Type locality. Divala, Chiriqui, Panama. 



Geogr. Distr. Central America. 



Genl. Char. Similar to the South American animal, but second 

 stripes much less broken into spots; hind foot larger. Skull larger; 

 palate narrower; audital bullae flatter. 



