44 FOSSIL ECHINI OF THE WEST INDIES. 



about 7 mm. in height. The ambulacral petals are visible on this 

 smaller specimen only. Petals I, V, and III measure 14 mm. in length 

 by 8 mm. in width. Petals II and IV measure 12 mm. in length by 

 8 mm. in width. 



Clypeaster placentoides is near to the Recent West Indian C. depressus 

 in some particulars, but the petals are rounded at the tips, not bluntly 

 pointed as in subdepressus. Also, the petals are flat, not markedly 

 arched. The test is much thicker at the edge than in a specimen of 

 subdepressus of the same size. 



Oligocene, El Jique de la Argolla, about 2 miles from San Antonio 

 Central, northeast of Guantanamo, Cuba, C. T. Ramsden's collection. 



Clypeaster meridanensis Michelin. 



Clypeaster meridanensis Michelin, 1850, Revue et Mag. Zool., vol. 2, p. 240; Mem. Soc. 

 Geol. de France, ser. 2, vol. 7, p. 136, plate 14, figs, la to /. A. Agassiz, 1883, Mem. 

 Mus. Comp. Zool., vol. 10, No. 1, p. 89. 



Test elevated dorsally, but very flat on base. 



Michelin gives only Tertiary in the environs of Merida, Yucatan. 

 A. Agassiz, however, records the species as "Miocene," Guadeloupe. 



Clypeaster oxybaphon, 1 new species. 



(Plate 7, Figures 3, 4; Plate 8, Figures 1 to 3.) 



The following is a description of this species : 



Test low, pentagonal in outline, elongate anteriorly, truncate poste- 

 riorly; thick and rounded on the margin, depressed in a dish-like fashion 

 dorsally, and in the center of the dish the proximal portion of the petals 

 with the apical disk rise in a slight eminence, moderately concave ventrally. 

 Ambulacral petals slightly raised above the general surface of the test; 

 petals gently rounded, but open at the distal tips. Poriferous areas are 

 sunken ; the pores are connected by well-marked furrows, the ridges between 

 which bear 8 or 9 small tubercles. The outline of both the inner and outer 

 poriferous areas present a gentle curve from the base to the distal end. 

 Petals I, V, and III are closely of the same length and width; II and IV 

 are shorter, but of about the same width as the others. The apical disk 

 is central in position, genital pores are large and sunken. Periproct well 

 removed from the posterior border of the test. Ambulacral grooves are 

 strongly marked, deepening toward the centrally placed mouth. Tubercles 

 are small, closely associated, and somewhat larger and more crowded on 

 the ventral side. 



The holotype measures 116 mm. in length, 102 mm. in width across 

 ambulacra II and IV, and about 17 mm. in height. Another and more 

 elongate specimen from Porto Rico measures 130 mm. in length, 

 91 mm. in width, and 24 mm. in height. In this specimen the periproct 

 is 4 mm. from the posterior border of the test. 



Clypeaster oxybaphon is very different from any other Recent or 



1 <5£ u/3&#a>j"= a shallow dish or saucer. 



