F. B. Loomis — Origin of the Wasatch Deposits. 368 



of the material likewise furnishes the same result. The upper 

 1000 feet of the Wasatch appear to overlap in time the base of 

 the Wind River, as shown by the fauna of the upper Buffalo 

 Basin beds. 



Appended are the descriptions of two new species from 

 these beds : 



Lambdotherium primaevum sp. nov. 



Type No. 254, consisting of upper molars 1 and 2 of the 

 right side and lower molars 1, 2 and 3 from the same side, the 

 specimen being from the Buffalo Basin, near Meeteetse, Wyo. 

 This species is fairly abundant at this horizon and is inter- 

 mediate in size between L. brownianum and L. popoagicum. 



Fig. 2. Lambdotherium primaevum. A, upper molars 1 and 2 ; B, lower 

 molars 1-3. Natural size. 



On the upper molars the parastyle, though strong, is not so 

 well developed as in the foregoing forms ; the paraconule is 

 well developed, but the metaconule is so annexed to the meta- 

 cone as to appear like a buttress of this cusp. The second 

 molar measures 12 mm transversely by 17 mm lengthwise. The 

 robust lower molars have the protoconid markedly bifid, while 

 the paraconid and hypoconid are each high crescents. The 

 heel of the last molar is a high shallow basin completely sur- 

 rounded by an outer rim. The three molars occupy 41 mm . 



Glyptosaurus obtusidens sp. nov. 



Type No. 133, a lower jaw of the left side, with five teeth ; 

 from Tatman Mountain, Wyo. Cotype No. 106, a ventral 

 shield from the same locality. 



The genus is characteristic of the Bridger beds, from which 

 eight species have been described, mostly larger than the 

 present one. The genus is characterized by pleurodont teeth 

 on the jaws, the presence of a surface of tiny teeth on the 

 pterygoids, and by osteoderms on the head and body, espec- 

 ially the belly, these osteoderms being characteristically orna- 

 mented. Cope* described some of the latter and attributed 



*Geog. Surv. West of 100th Mer., vol. iv, p. 42, 1877. 



