624 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 59. 



plane is 106 mm.; the width across the proximal articular surface is 

 46 mm.; that across the distal surface, 38 mm. At the middle of the 

 length the fore-and-aft diameter is 24 mm.; the side-to-side diameter, 

 27 mm. The bone resembles closely the corresponding one of Pro- 

 camelus major. 15 The former is, however, a slightly stouter bone, as 

 may be seen in comparing the measurements just given with those of 

 the table on page 60S. On the underside of the distal end the lower 

 articular surface ascends a height equal to one-third the total length 

 of the bone; in P. major, only 0.27 of the length. The fore-and-aft 

 width of the upper articular surface in P. major equals 44 mm.; in 

 the bone from Arizona, only 39 mm. The fore-and-aft thickness of 

 the distal end of the bone in P. major is 36 mm.; in the other bone, 

 32 mm. These differences appear to be of specific value. 



There is present in the collection a first phalange (Cat. No. 10177), 

 which appears to belong to the hinder foot of this species (pi. 123, 

 fig. 5) . It is that of a rather young animal, inasmuch as the epiphy- 

 sis is missing from the upper end. The bone is there somewhat 

 damaged. Its original length was very close to 85 mm. The side- 

 to-side diameter at the middle of the length is 21 mm.; the fore-and- 

 aft, 20 mm. The width of the distal articular surface is 25 mm. 

 The hinder face is concave both up and down and from side to side. 



There is present the greater part of one second phalange, probably 

 belonging to a front foot (Cat. No. 10165). The upper articular 

 surface is 43 mm. wide. 



PROCAMELUS LONGURIO. new species. 

 Plate 120, fig. 8; plate 123, figs. 3-4; plate 124, fig. 4. 



Type specimen. — A right hinder cannon bone, lacking the lower 

 split end. (Cat. No. 10166). 



Type locality. — -Coconino Forest plateau, Arizona. 



Type formation. — Lower Pleistocene. 



Diagnosis.— Animal with long and slender limbs and, as shown by 

 a referred axis, long necked, the hinder cannon bone, on the middle 

 third of the shaft, with rounded front and lateral faces and with a 

 deep hinder groove (pi. 120, fig. 8.) 



A smaller camel than the dromedary is indicated by an injured 

 axis, the greater part of a hinder cannon bone, and some first pha- 

 langeals. It appears to have been a slender, long-necked, and long- 

 legged animal. The axis (Cat. No. 10167) lacks the hinder end. In 

 all probability this missing portion was in the deposit, but was not 

 collected. In size the bone is intermediate between that of the llama 

 and that of the dromedary. An estimate based on the axes of the 

 species just mentioned indicates that the length of the centrum of 



l * Leidy and Lucas, as cited, pi. 18, fig. 2. 



