EXPLANATION OF PLATES 283 



reptilian character to make it worth while describing them until further 

 evidence of their identity is forthcoming. 



That the present genus is not a pelycosanrian is, of course, evident; 

 its relationships with the cot3dosanrians are more apparent. Nevertheless, 

 the great differences in the structure of both vertebrse and limb bones 

 from anything known among either the diadectid or pariotichid types 

 render the exact position of the genus very doubtful. Possibly, as I have 

 said, it may eventually tuTn out to be congeneric with some one of the few 

 forms in which the vertebrae and limb bones are yet unknown, especially 

 Pantylus. 



EXPLAITATION- OF PlATES 



All the figures are by the author, from specimen number 647. and of natural 

 size, save where otherwise noted 



Plate 6. — Cacops aspidcphorus Will. Top view of skull. Specimen number 

 649. 



Plate 7. — Cacops aspidephorus Will. Palatal view of skull. Specimen num- 

 ber 649. 



Plate 8. — Cacops aspidephorus Will. Figure 1, side view of skull ; specimen 

 number 649. except posterior part of mandible; figure 2, upper view of left 

 mandible. 



Plate 9. — Cacops aspidephorus Will. Vertebral column, from right with 

 sacral ribs. 



Plate 10. — Cacops aspidephorus Will. Figure 1, scapula, with attached clei- 

 thrum and clavicle; a, from within; h, from without; figure 2, Aspido- 

 saurus sp. Broili, spines of dorsal vertebrae; a, from the left; 6, from in 

 front; figure 3, Desmospondylus anomalus, posterior dorsal vertebrae; a, 

 from the left ; 6, intercentrum from below ; both figures twice natural size. 



Plate 11. — Cacops aspidephorus Will. Figure 1, pectoral girdle from above ; 

 figure 2. left humerus, from inner side ; figure 3, the same from outer side : 

 figure 4, the same from in front; figure 5, the same from behind. 



Plate 12. — Cacops aspidephorus Will. Figure 1, various toe-bones of left 

 hind foot; figure 2, tarsals of same foot; figure 3, carpals and phalanges of 

 left front foot ; figure 4, pelvis, from below ; figure 5, twelfth vertebra, from 

 in front, the left pleurocentrum omitted; figure 6, dorsal shield of same 

 vertebra ; a, from above ; &, from below ; figure 7, hypocentrum ; figure 8. 

 ribs, as numbered, 3 and 5 of the left side, the others from the right. 



Plate 13. — Cacops aspidephorus Will. Figure 1, pelvis, from the right; figure 

 2, left femur, from in front ; figure 3. the same, from behind ; figure 4, 

 the same, from within ; figure 5, the same, from without. 



