32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I45 



Cooke (1959, p. 36) referred his specimens of this species from 

 South Carolina to Clypeaster subdepressus Gray. However, C. cras- 

 sus has a much thicker margin and the area between its margin and 

 the ends of its petals is flat or depressed whereas it slopes marginally 

 in C. subdepressus. In C. crassus petal III is more widely open and 

 not as long relative to the other petals, and the test is less elongate 

 and smaller. 



Occurrence. — Florida, Tamiami formation, loc. 9, 10. South Caro- 

 lina, U.S.G.S. 18759, Intracoastal Waterway canal 1.5 miles south- 

 west of highway bridge near Nixons Crossroads, about 15 miles 

 northeast of Myrtle Beach. 



Types. — Holotype U.S.N.M. 648142, loc. 9; figured specimens, 

 U.S.N.M. 648143, loc. 9, 648176, U.S.G.S. 18759. 



CLYPEASTER SUNNILANDENSIS Kier, new species 

 Plate 3, figure 3; plates 12, 13 



Diagnosis. — Species characterized by large, low, elongate test with 

 petal III open distally. 



Material. — Fourteen specimens. 



Shape. — Large, largest specimen 157 mm long, smallest 119 mm, 

 average 140 mm ; test elongate, average width 85 percent of length ; 

 marginal outline pentagonal, anterior pointed, posterior truncated, 

 interambulacra 4, 1 slightly indented at margin; area between mar- 

 gin and ends of petals sloping marginally; test low, average height 

 20 percent of length ; margin thin, thickness approximately 7 percent 

 of length ; petaloid area inflated, adoral surface slightly depressed. 



Apical system. — Central to slightly anterior, five genital pores, 

 small ocular plates, madreporite star-shaped. 



Ambulacra. — Petals broad, of unequal length, anterior petal (III) 

 longest, 20 percent longer than anterior paired petals (II, IV) ; pos- 

 terior paired petals intermediate in length ; anterior petal open, gap 

 at distal end of petal averaging 6.2 mm in width or 4.4 percent of 

 length, posterior petals open in some specimens ; interporiferous zone 

 approximately twice width of poriferous zone; in specimen 139 mm 

 long 75 pore-pairs in poriferous zone of petal III, 64 in petal II, 

 69 in petal I, in specimen 119 mm long, 68 pore-pairs in zone of 

 petal II, 57 in petal IV. 



Periproct. — Inframarginal, located near posterior margin, on speci- 

 men 130 mm long, 4.1 mm from posterior margin, opening irregular 

 in outline, elongated transversely. 



Peristome. — Central, shape not preserved on any specimen. 



