EXPLANATION OF PLATE XL 

 (All figures after Clark.) 



TREMATOPYGUS CRUCIFERUS (Morton), p. 289 



1-4. Dorsal, ventral, lateral and posterior views of a complete in- 

 dividual. 



5. Lower portion of the petaloid region of the right postero- 



lateral ambulacrum. 



6. Much enlarged view of several of the same ambulacral plates. 



7. Apical disk, enlarged. 



8-9. Two views of a tubercle, from above and from the side. 

 Vincenton.'n limesand; Timber Creek. 



CATOPYGUS OVIFORMIS Conrad, p. 291 



10-13. Dorsal, ventral, lateral and posterior views of a complete 

 individual. 



14. Right postero-lateral ambulacrum, enlarged. 



15. Several ambulacral plates, highly magnified. 



Vincentown limesand; Timber Creek. 



CATOPYGUS PUSILLUS Clark, p. 292 



16-19. Dorsal, ventral, lateral and posterior views of a complete 

 individual. 



Merchantville clay-marl. 



902 



