OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 287 



arm spines in Ophiogymna elegans (pi. 103, fig. Id) and in O. ful- 

 gens (fig. 8e), 0. pulchella (fig. 5#), and O. funesta (figs. 9a and e) 

 will show these resemblances. 



I may state that in all these species the tentacle scale is completely 

 lacking, or if it exists it remains only slightly developed and dis- 

 appears at a short distance from the disk, which is the case, as I 

 have just said, in 0. fulgens and in O. pulcJiella. In the new species 

 the tentacle scale is also almost completely lacking. 



For all these reasons I believe that the two species which I had at 

 first assigned to the genus Ophiothrix 0. fulgens and 0. pulcliella 

 as well as the new species discovered by the Albatross, which is very 

 closely related to them, are better placed in the genus Opliiogymna 

 than in the genus Ophiothrix. I may add that still another species 

 which I have recently described and assigned to the genus Ophio- 

 thrix O. convoluta from the Caribbean Sea has, like the preceding 

 forms, which it quite resembles in its general appearance, flexible 

 and very contorted arms, and is without the tentacle scale ; although 

 I have not had occasion to study the articular facets of the arms, I 

 believe it necessary to assign it to the genus Ophiogymna. 



To sum up, I believe that it is necessary at present to refer to the 

 genus Ophiogymna the six following species : 



Ophiogymna elegans (Ljungman) (genotype). 



Ophiogymna pellicula (Duncan). 



Ophiogymna fulffens (Kcehler). 



Ophiogymna pulcJiella (Kcehler). 



Ophiogymna convoluta (Kcehler). 



Ophiogymna funesta, new species. 



In accordance with the preceding remarks, I propose to modify 

 and to complete the diagnosis of the genus Ophiogymna as follows : 



Ophiotrichidae with the arms very long and narrow, very flexible 

 and twining, capable of rolling up in every plane thanks to a struc- 

 ture of the articular facets of the vertebrae simpler than that found 

 in the genus Ophiothrix. The disk and even the arms may be cov- 

 ered by an integument which more or less completely conceals the 

 outlines of the subjacent plates; these plates themselves are only 

 slightly developed on the disk; they are lacking on the ventral sur- 

 face, and on the dorsal surface they are separated from each other by 

 soft areas. The upper arm plates are present, but concealed under 

 the integument and more or less broken up; the cylindrical and 

 opaque arm spines show well developed denticulations only in their 

 terminal regions. The tentacle scale is absent, or if it occurs it is 

 reduced and disappears at a short distance from the disk. 



