54 



MAURICE G. MEHL 



several distinct types and a great variation in size. All bear a 

 more or less prominent antero-posteriorly directed carina on the 

 dorsal surface and are concave below from side to side to some 

 extent at least and often sharply so. The dorsal surface of all is 

 deeply sculptured by small, rounded, closely crowded pits. While 

 the anterior and posterior edges are smooth, the lateral edges of 



Fig. 2>-~Caimanoideus Visheri, right femur; a, from below; b, from above; 

 c, from behind; three-fourths natural size. 



most of them indicate a more or less firm union with an adjacent 

 plate. In some plates, this union is indicated on one margin only, 

 and a few apparently were entirely free. The plates were prob- 

 ably arranged in more or less rigid transverse rows of five units 

 at least, and, in much probability, seven units for certain regions of 

 the back. Fig. 4 indicates the apparent arrangement of the plates. 

 As pointed out above, the affinities of this form with the genus 

 Alligator are marked. This is shown chiefly in that the fourth 



