PLATE IV. 
1-2. Porocidaris Sharreri A. Ag. 
Fig. 1. Portion of test of specitiien measuring nearly three inches? in diameter. Seen in profile. 
Fig. 2. Abactinal system of same, both figures somewhat enlarged. 
3-23. Salenia Pattersoni A. Ag. 
Fig. 3. Abactinal system of specimen 18 mm. in diameter. 
Fig. 4. Actinal system of same. 
Fig. 5. Portion of test of same, seen in profile, showin^:; primary coronal plates above ambitus, facing 
the median interambulacral line. 
Fig. C. Portion of test of same above the ambitus, seen in profile facing the median ambnlacral line. 
Fig. 7. Portion of ambulacral area of same, showing the llemicidaris-like arrangement of the tubercles 
at the base of the andnilacral area near the actinostorae. 
Fig. 8. Primary s})ine of same. Natural size. 
Fig. 9-11. Ambulacral papillce of same, magnified. 
Fig. 12-14. Porocidaris-like interambulacral spines, near actinostorne, magnified. 
Fig. 13. Test of specimen 12 mm. in diameter, seen from the aliactinal side. 
Fig. IG. Portion of test of same, below and at ambitus, seen in profile, facing the median ambulacral line 
and showing the Hemicidaris-like ambulacnrl tubercles. 
Fi.g. 17. Actinal system of same. 
Fig. 18. Abactinal sy.stem of specimen 10 mm. in diaineter. 
Fig. 19. Actinal system of same. 
Fig. 20. Portion of test of same, above ambitus, seen in ]irofilf, facing the median interambulacral line. 
Fig. 21. Portion of test of same, below and at andiitus, seen facing the median ambulacral line, to show 
the Hemicidaris-like arrangement of the ambulacral tubercles. 
Fig. 22. Young Salenia 6.5 mm. in diameter, seen from the actinal side. 
Fig. 23. Abactinal system of same. 
