172 Bvlletin Vanderbilt Marine Museum, Vol. VII 



A second diagnostic character exists in the apical system, which 

 is almost entirely devoid of tubercles, except for a single series of 

 larger tubercles along the margins of the genital and ocular plates 

 and a few small tubercles on the periproctal plates which carry 

 one, or a very few, small tubercles each. Minute glassy beadlike 

 warts closely pave the apical plates. The apical system is circular 

 in outline, the oculars all being normally exsert, each plate being 

 wedge-shaped, with convex outer margin. 



The interporiferous zone of the ambulacra is slightly sunken 

 and almost bare, this condition being another distinctive charac- 

 teristic of metularia. 



The four specimens from Pearl Harbor give the following 

 measurements, expressed in millimeters : 



Test : Primary Spines 

 Horizontal Diameter Vertical Diameter Length 



21 14 8.5 to 14.5 



18 13 12 " 13.5 



19 14 12 " 14 

 13 8.5 11 " 11.5 



One of these specimens is shown in the accompanying plate. 

 Excellent illustrations of the representative pedicellariae of Euci- 

 daris metularia are given by Agassiz and Clark (1907), in the 

 Memoirs of the Museum of Comparative Zoology, volume XXXIV, 

 plate 1, figures 3 to 7. 



References : Echinometra mu^cosa amhoiensis, Seba, A., Locupl. 

 rerum Nat. Thes., 1734-65, Amsterdam, t. II, pi. 13, figs. 

 10, 11. 



Cidarites metularia, Lamarck, J. B., Hist. Nat. Anim. s. Vert., 

 1816, t. Ill, p. 56 ; ed. II, 1840, t. Ill, p. 381.— Deslongchamps, 

 E. E., Encycl. Meth., 1825, t. II, p. 195, pi. 134, fig. 8 (a repro- 

 duction of Seba's figure) . 



Cidaris metularia, Agassiz, A. and DeSor, P. J. E., 1846, Cat. 

 Rais. des. Ech. in Ann. des Sci., ser. 3, t. VI, p. 22 (324).— 

 Doderlein, L., in Wiegmann's A. F. A., Archiv. f . Naturg., 

 1885, Bd. LI, pt. I, p. 75. 



Eucidaris metularia, MoRTENSEN, Th., Monogr. of Echinoidea, 

 pt. I, Cidaroidea, 1928, p. 386, pi. 41, figs. 1-8, pi. 73, fig. 6, 

 pi. 86, figs. 11-14 (contains earlier references) . 



