EXPLANATION OF PLATES 

 Plate 1 



Page 



Arbacia crenalata Kier, new species 11 



1, 2, 3, Adapical, adoral, and side view of holotype, U.S.N. M. 

 648133, from the "Buckingham fades" of the Tamiami formation, 

 loc. 20. 



4, Enlarged view of portion of peristome of same specimen, X 2. 



5, Enlarged view showing ornamentation in interambulacrum of 

 same specimen, X 2. 



Arbacia improcera (Conrad) 14 



6, Enlarged view showing ornamentation in interambulacrum of 

 U.S.N.M. 166487 from the Yorktown formation on Smith Creek 

 i mile below Suffolk, Va., waterworks dam, X 2. 



Plate 2 



Lyt echinus variegatus plurituberculatus Kier, new subspecies 15 



1, Adapical view of holotype, U.S.N.M. 648149, from the Caloosa- 

 hatchee formation, loc. 6, X li- Adoral view of same specimen on 

 pi. 9, fig. 1, side view pi. 10, fig. 4. 



2, View of ambulacrum at ambitus of same specimen figured in pi. 1, 

 fig. 1, X 4. 



Lytechinus variegatus variegatus (Leske) 15 



3, View of ambulacrum at ambitus of U.S.N.M. 648151 from the 

 Recent at Boca Inlet, Fla., X 4. 



Plate 3 



Lytechinus variegatus plurituberculatus Kier, new subspecies 15 



1, Adoral view of holotype figured in pi. 8, fig. 1, X li- 

 Echinometra lucunter (Linnaeus) 19 



2, View of a fragment, U.S.N.M. 648152, from the Caloosahatchee 

 formation, loc. 6, X 2.3. 



Clypeaster sunnilandensis Kier, new species 32 



3, Right side view of U.S.N.M. 648134 from the Tamiami forma- 

 tion, loc. 9, X 1- Adoral view of same specimen pi. 3. 



Plate 4 



Echinometra lucunter (Linnaeus) 19 



1, 2, 3, Adoral, adapical, and side view of U.S.N.M. 648153 from 

 the Caloosahatchee formation, loc. 6, X H- 

 Lytechinus variegatus plurituberculatus Kier, new subspecies 



4, Side of holotype figured on pi. 8, fig. 1, 2; pi. 2, fig. 1, X lb 



6o 



