m 



HYSTEICID^— FOSSIL SPECIES. 



397 



B 



TAHLBlV.—Liatoftpe^mena 0/ EuETnizoN nonsATUS far. EPiXANTnus. 



* In the Museum of Comparative Zoology, Cambridge, Mass. 



EXTINCT NORTH AMERICAN PORCUPINES. 



i .i 



Two forms of extinct North American Porcupines have thus far been 

 indicated, (lcscril)ed in each case from detached teeth. Hence their relation- 

 ship to the existing species is very imperfectlj known. 



Dr. Leidy has described* a species from two detached molar teeth, dis- 

 covered by Dr. Hayden in the Pliocene deposits of Dakota, which he refers 

 to Hystrix, under the name Hystrix venustus. Of these teeth, Dr. Leidy 

 says : '' They apparently indicate a species of Porcupine, but in structure are 

 unlike those of the recent American Porcupine, Erethizon dorsatus, and ex- 

 hibit a more evident relationship with those of the Crested Porcupine, Hystrix 

 cristata of Europe." As is well known, the genus Hystrix belongs to a very 

 different group from the Porcupines of the New World, and has not been 



• Jouru. Acad. Not. Sol. PUII., Scl wr., v, 1809, 313 ; U. 8. Oool. Survey of WyomiiiR for 1870 (1871), 304. 



