NO. 5 TERTIARY ECHINOIDS FROM FLORIDA — KIER 35 



five genital pores, genital pore 5 eccentric to right on most specimens. 

 Ambulacra. — Petals broad, closing distally, interporiferous zone 

 wider in petal III than in other petals; anterior petal III, posterior 

 paired petals (V and I) of approximately same length (see table 2) ; 

 anterior paired petals shorter than others, in most specimens petal II 

 shorter than petal IV ; in smallest specimen 76 pore pairs in petal 

 III, 59 in II, 61 in IV, 82 in V or I ; in larger specimen 100 mm long 

 92 pore pairs in petal III, 70 in II, 81 in IV, 118 in V or I. 



Table 2. — Encope michelini imperforata Kier, new subspecies 



Length of test 



109 



in 

 39 



II 



Length of petal 

 IV 

 31 



V 



41 



I 



41 



100 



32.5 



27.3 



29.2 



36 





106 



33 



25.1 



25.1 







115 



36 



27.2 



29.4 



36 



36.5 



122 



38 



32.3 



32.5 



39.5 



39 



82 



23 



17.1 



18.4 



22.3 



22.4 



90 



32.5 



16.8 



17.8 



22.8 





Adoral plate arrangement. — Sutures not visible on specimens. 



Periproct. — Opening longitudinal, located one-third distance from 

 peristome to posterior margin. 



Peristome. — Central, circular. 



Comparison zvith nominate subspecies. — This subspecies is similar 

 in all respects to the nominate subspecies except that its posterior 

 closed lunule is quite small or entirely absent. In one-half of 

 the specimens of Encope michelini imperforata the lunule is absent 

 whereas in the nominate subspecies it is apparently always present. 

 I examined 186 specimens of the nominate subspecies, and in all of 

 them this lunule was present. 



Remarks. — This subspecies, as with the nominate subspecies, is 

 very variable in the shape of the test. The ambulacral notches are 

 very well developed in many of the specimens but completely absent 

 in others. 



Occurrence. — Post-Caloosahatchee, pre-Fort Thompson, loc. 1. 

 Caloosahatchee formation, loc. 4, 6, 7. Tamiami ("Buckingham" 

 facies) formation, loc. 23. 



Ty/j^— Holotype, U.S.N.M. 648167, loc. 2; figured specimens, 



Figs. 25-30. — Encope michelini imperforata Kier, new species : 25, U.S.N.M. 

 648169, loc. 7; 26, U.S.N.M. 648167, loc. 2; 27, U.S.N.M. 648170, loc. 4; 28, 

 U.S.N.M. 648168, loc. 6; 29, U.S.N.M. 648171, loc. 4; 30, U.S.N.M. 648172, 

 loc. 4. All approximately X i- 



