68 



osborn: oligocene, miocene, pliocene equid^e. 



fragments, Amer. Mus. 13S09, from Porcupine Creek; fragment of lower jaw, p2-m3, Amer. Mus. 12928, from Eagle Nest 

 Butte; upper milk molars, unworn, Amer. Mus. 12917a, from Porcupine Creek, Amer. Mus. 12917c. 

 Type figure. — Plates 3.7, 4.9, text Fig. 4G of this Memoir. 



Characters. — (Matthew, 1913) (1) Same size as Miohippus annectens and M. anceps. (2) Premaxillary alveoli 

 indicate incisors and canine of exceptionally large size; (3) p 2 of less transverse but greater antero-posterior diameter 

 than M. anceps and M. annectens; (4) p 2 relatively narrow and elongate, p 1 relatively large; (5) metaloph not united with 

 ectoloph; (6) premolars with somewhat larger parastyle, especially on p 2 , than in M. annectens; (7) no internal cingula, 

 no intermediate basal cusps; (8) hypostyle better developed on true molars. 



In a referred juvenile specimen, Amer. Mus. 12917a, the deciduous premolars resemble the permanent premolars 

 in the crown pattern and transverse diameter. Metaloph separated from ectoloph. (1) In a referred Amer. Mus. lower 

 jaw, metastylid quite distinct, p2-ni3, although less well separated than in Parahippus; (2) metalophid not united with 

 metastylid until tooth is well worn. 



The name gemmarosoe is founded on the Latin for the word Rosebud, the name which has been applied by Matthew 

 to the beds from which this specimen was secured. 



