i6o MAURICE G. MEHL 



Palaeorhinus, with slightly different orientation to bring out its 

 similarity with another specimen, Fig. 20. This second specimen 

 is somewhat crushed laterally and is slightly smaller and more 

 slender than the first. They probably represent two different 

 species but the figures indicate that they are generically the same, 

 or at least should be so considered till evidence to the contrary is 

 forthcoming. A brief notice of this new form follows: 



NEW GENUS ? 



The material upon which this form is based consists of several 

 extremities (both proximal and distal) of limb bones, several ver- 

 tebrae from various regions of the body, and many other frag- 

 ments, besides the ilium figured above (Fig. 20). The specimen 

 is a part of the collection of the University of Chicago expedition 

 of 1904 and comes from the Popo Agie River region of the Trias 

 of Wyoming. 



One of the vertebrae has been freed from the matrix and shows 

 characteristics not at all like those of the phytosaurs. It is a 

 middle or anterior thoracic vertebra with the capitular articulation 

 in a transitional stage in its elevation from the centrum to the arch. 

 The centrum is spool- or hourglass-shaped with anterior and pos- 

 terior faces slightly concave and is much constricted laterally along 

 its midlength. It is 54 mm. long and 10 mm. wide at the center 

 (this width is probably lessened by pressure) . The articular faces 

 are sKghtly oblong in outline, about 32 mm. wide and 39 mm. high. 

 The diapophyses are in the form of thin horizontal plates confluent 

 anteriorly with the articular faces of the zygapophyses and widen- 

 ing regularly posteriorly. Suddenly, near the posterior ends, they 

 thicken below into the articulation for the tuberosity. At this 

 point the diapophyses are about 56 mm. from tip to tip. They are 

 supported at the posterior end by two thin diverging buttresses, one 

 directed toward the upper posterior articular face of the centrum 

 but not reaching this point, the other confluent with the capitular 

 articulation on the upper anterior articular face of the centrum. 

 The distance between the articular faces for the tuberosity and 

 that of the capitulum is some 30 mm. The total height of 

 the vertebrae is 96 mm. The upper portion of the spine is 



