642 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



Family OPHIACANTHID^. 



This family is in the same category as the two preceding, the species which 

 normally live attached to arborescent organisms frequently straying on to the 

 pentacrinites and more rarely on to the comatulids. I have seen specimens of 

 various species of Ophiacantha on Metacrinus taken in the Philippines. 



OPHIOLERE8 SCORTEUS LYMAN. 



P. H. Carpenter records a specimen of this species which he found entangled 

 in the cirri of a specimen of Eumorphometra hirsuta dredged by the Challenger 

 near Marion Island in 140 fathoms. 



Family OPHIOCOMID^}. 



The association of ophiurans of this family with crinoids can scarcely be more 

 than accidental though in view of the abundance of both on certain reefs in the 

 East Indian region, and the activity of the former, especially when young, it must 

 be more or less frequent. 



OPHIOCOMA, SP. 



Lieutenant Potts states that at Torres Strait he found a young Ophiocoma, too 

 small for accurate determination, on Comanthus annulatus. 



Family AMPHIURID^. 



Some of the species in this family, as the species of Ophiactis, are more or less 

 strictly commensal ; others, as the species of Ophiopholis, commonly conceal them- 

 selves in rootlike growths or cling to arborescent organisms; while others, as the 

 species of Amphiura, Amphipolis, etc., live on or in mud, sometimes burrowing 

 downward for a considerable distance. These last are sometimes phosphorescent. 



The species of the first group will naturally sometimes be found on crinoids, 

 and those of the second group will occasionally occur among the cirri of the 

 comatulids and on the stems of the pentacrinites inhabiting the same regions. 



OPHIACTIS DELICATA H. L. CLARK. 



Lieut. F. A. Potts reported a specimen of an undetermined species of the genus 

 Ophiactis as commensal on comatulids at Torres Strait. 



Dr. H. L. Clark described this specimen under the name of Ophiactis delicata. 



It was found on an example of Comanthus annulata in 18 fathoms off the 

 southwestern reef at Maer, Murray Islands, Torres Strait. 



IOPHIACTIS, SP. 



Mr. H. C. Chadwick in 1908 recorded a specimen of Pleterometra savignii from 

 Ul Shubuk, on the Red Sea, which, when living, was whitish with a violet tinge 

 and with patches of darker color and of yellow, from which were taken 15 ophiurans 

 that lived with their arms wrapped around those of the crinoid, and of which the 

 color on the whole resembled that of their host. 



