MURID.E.— CHRYSOMYS. 223 
The Poucuen Goren. Geomys bursarius. 
Baird, Mamm. N. America, p. 372. pl. 50. fig. 2 (skull), 1859. 
Ascomys canadensis, Schreb., Saugth. iii. p. 8383, 1843; Abh. K. Baier. 
Acad. Miinchen, xxii. p. 327 (skeleton), 1846. 
The Suort-HEADED Gorpuer. Geomys breviceps. 
Baird, Mamm. N. America, p. 87. pl. 52. fig. 2 (skull), 1859. 
THOMOMYS. 
Teeth :—Incisors | ; Molars $3 ;=16. 
The Carirornian Gopoer. Thomomys bulbivorus. 
Baird, Mamm, N. America, p. 389. pL 50. fig. 3 lh 52. tig. 1 
(skull).— Brandt, Mém. Acad. St. Pétersb. vii. pl. 5a. figs. 1-9 (skull 
and dentition). 
*a, Skull. California. 
The Sonora Gopner. Thomomys umbrinus. 
Baird, Mamm. N. America, p. 399. pl. 83. fig. 5 (skull), 1859. 
Geomys umbrinus, Richardson, Charlesworth’s Mag. Nat. Hist. 1839, 
p. 596, fig. 71 (skull). 
SACCOPHORUS. 
Teeth :—Incisors = ; Molars 3 ;=16. 
The Tuean. Saccophorus mexicanus. 
Ascomys mexicanus, Schreb., Siugth. pl. 239 B (dentition).—Brandt, 
Mém. Acad. St. Pétersh. vii. pl. 5a. figs. 10-12 (dentition). 
a. Skull. Mexico. 
The Quacuit. Saccophorus quachil. 
Cervical vertebre.............. 7 
Dorsal: .cohae aces ceaeealio tach geeackons 12 
TM bar: ears kee wa da.e Bootes 7 
Sa6TaD) epee dooenhas ae 5 
Catal cats. eapscecastssnies wiengi seed wind teas eee 16 
a. Skeleton. Mexico. From M. Sallé’s Collection. 
CHRYSOMYS. 
The Gorpen Morr Rat. Chrysomys splendens. 
Bathyergus splendens, Riippell, Faun. ae taf. 12 (skull), 1835-40. 
— Waterhouse, Mag. Nat. Hist. viii. p. 84. pl. 2. fig. 3 (skull), 1842. 
