52 
As pointed out by Ly man O. nigra recalls to some extent 
the genus Ophioconis. However, this resemblance is evidently a 
more superficial character. Ophioconis (with its subdivisions) is 
referred by Matsumoto — and correctly I do not doubt — to 
the family of Ophiodermatidæ; its appressed arm-spines alone afford 
a very prominent difference from O. nigra ; there is no necessity 
for a detailed discussion of the relations between these forms; 
surely nobody would maintain in earnest that O. nigra could be- 
long to that genus. 
But then Ophiacantha ! In view of the faet that the Ophiacanth- 
idæ and the Ophiocomidæ are referred by Matsumoto to two 
different orders, the former to the Læmophiurida, the latter to the 
Chilophiurida, one should expect that Clark had produced very strong 
reasons for removing O. nigra to Ophiacantha. This he has not at 
all done. Without entering on a discussion of Matsumoto’s orders, 
which I do not think quite acceptable — especially the order Læm¬ 
ophiurida, conprising the Ophiacanthidæ and the Hemieuryalidæ, 
is, in my opinion, quite unnatural — I must State that I find the 
referring of O. nigra to the genus Ophiacantha quite unjustifiable. 
In regard to the inner anatomy it is about intermediate between 
Ophiacantha and the typical Ophiocoma’ s, though somewhat nearer 
to the latter. The wings of the first vertebræ are decidedly larger 
than in Ophiacantha, though not nearly so large as in Ophiocoma. 
(— Apparently the strong development of the wings in Ophiocoma 
has some connection with the peculiar mouth armature; the power- 
ful muscles attached to these wings must enable it to very active 
movements with its jaws, and the enamel point of the teeth in the 
same time bear witness of an exceptional masticating power —). 
In regard to the peristomial plates and the articulation between 
the genital plate and the radial shield it is mueh more like Ophio¬ 
coma than Ophiacantha. Thus there is no support for its affinity 
to Ophiacantha to be found in its inner anatomy. And then there 
is a very essential difference, which Clark appears to have com- 
pletely disregarded, viz. the presence of tooth papillæ in O. nigra , 
which character is not found in Ophiacantha. And — in spite of 
all efforts, especially by Matsumoto, to find characters of greater 
systematic value — it is hardly possible to point out such struct- 
ures of greater value than the mouth armature. But this character 
