Verrill, Notes on Eadiata. 267 



The color seems to have been about like that of the two preceding 

 {O. Oi'stedli and 0. virescens). 



Diameter of disk 5""" ; length of arms 20""". 



Puntarenas and ReaU'jo." 



In a<l(lition to the preceding species of OjJiiactis there is a single 

 imperfect specimen that may belong to an undescribed species. 



It has larger radial shields than O. simplex, separated by a row of 

 about thi'ee scales, no spines apparent on disk ; five arm-spines, the 

 upper one very short, the middle one longest ; upper arm-plates short, 

 transversely oblong, nearly three times broader than long, with nearly 

 straight outer and inner edges and slightly rounded sides ; month- 

 shields rounded ; one mouth papilla on each side of mouth slits ; under 

 arm-plates somewhat octagonal, outer edge convex. 



It has about the size and proportions of our largest 0. virescens, 

 but has no lobe on the outer edge of upper arm-plates and differs in 

 other particulars. It is probably nearest to 0. simplex. 



The color is dark greenish above. 



Until more specimens have been examined, it appears undesirable 

 to apply a new name to this form. 



Ophiothrix Spiculata LeConte, op. dt., p. 318; Lrman, op. cit, p. 167. 



This species is very al>undant at Panama and the Pearl Islands, 

 clinging to sponges, Gorgonifc, etc., whence Mr. Bradley has sent 

 upwards of t wo iundred specimens. He has also sent it from Realejo, 

 Nicaragua, and Acajutla, San Salvador. It occurs from low water to 

 4 fathoms. 



Our largest specimens have arms about 3 inches long, and the disk 

 •5 in diameter. 



The color, in alcohol, is usually light cobalt-blue or bluish purple, 

 often with every fourth or fifth lower arm-plate red or brownish. 

 Some :pecimens have spots of red on the disk and more or less on the 

 upper side of the arms. In life the color is described as fuscous above 

 and paler beneath ; or greenish with violet upper arm-plates, and 

 occasional red plates on the lower side of the arms. 



It is allied to 0. violacea of Aspinwall and the West Indies,* but 

 differs in having longer arm-spines and in several other characters. 



The disk usually has the centre and a band radiating to each inter- 

 brachial margin and to the base of each arm covered with numerous, 

 very short, branching spines, with more or less numerous, long, slen- 

 der, thorny spines scattered among them. The arm-spines are long 

 and slender, thorny, the next to the upper one longest. 



* Recently separated from the Brazilian violacea and named 0. Caribma by Lutken. 

 — Reprint. 



