A FOSSIL REPTILE. 743 
belong to the same species. The female skeleton is, however, 
much more lightly built, having narrower and more slender limb- 
girdles, and limbs which are less than three-quarters as long as 
those of the male skeleton and much less robust. Mr. Boulenger 
tells me that differences of this kind often distinguish the 
Text-figure 5. 
Procolophon trigoniceps. 
Restoration of the skeleton of a male, all the bones except those in dotted 
outline being drawn from a single individual. X 2. 
