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Article IX.—A REVISION OF THE LOWER EOCENE WASATCH 
AND WIND RIVER FAUNAS. ~ 
By W. D. Matruew anp WALTER GRANGER. 
Part Il. ORDER CONDYLARTHRA, FAMILY HYOPSODONTID A. 
By W. D. MatrHew. 
In the present revision the Condylarthra were assigned to Mr. Granger, 
the Insectivora, including Hyopsodontide to Dr. Matthew. The transfer 
of this family to the Condylarthra was not decided upon until after the 
detailed studies were completed; it appeared advisable therefore to place 
it in a separate section from the Phenacodontidse and Meniscotheriide 
revised by Mr. Granger. ! 
Following is the diagnosis of the order as here understood: 
Order Condylarthra. Herbivorous or omnivorous placentals with complete 
dentition, five-toed feet, ball-and-socket ankle joint and small brain. Upper molars 
low-crowned, rounded trigonal or quadrate with five or six principal cusps, the para- 
and metaconule distinct or strong; lower molars with four principal cusps, trigonid 
not elevated; third lobe of m; short or absent. Posterior premolars simple or pro- 
gressively molariform; anterior premolars, canine and incisors simple, little differen- 
tiated, usually in continuous series. Humerus with supratrochlear vacuity and 
entepicondylar foramen. Ulnar shaft wide and stout; a third trochanter on femur; 
fibula complete, wholly separate from tibia. Carpal bones moderately displaced 
(becoming nearly serial in Phenacodus); tarsals serial. Astragalus with distinct neck 
and ball-head, astragalar foramen present except in later Phenacodonts. Manus 
and pes mesaxonic, pollex and hallux not opposable. Phalangeal joints more or less 
distinctly of hinge type; unguals narrow, claw-like, or broadened into flat hoofs. 
Five families are at present included, the fifth provisionally. 
1. Mioclenide. Bunodont; hypocones of upper molars absent or rudimentary; 
premolars simple. Unguals unknown. Paleocene. 
2. Hyopsodontide. Bunodont, cusps round-conic, hypocones of upper molars 
progressively strong, lower molar cusps alternating; posterior premolars progressively 
complex. Unguals claw-like. Lower to Upper Kocene. 
3. Phenacodontide. Bunodont, with tendency to polybuny, or sublophodont, 
Hypocones of upper molars strong, cusps of lower molars opposite; posterior pre- 
molars progressively complex. Unguals progressively broadened into hoofs. Paleo- 
cene and Lower Eocene. 
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