464 Mr. E. A. Smith on a new Form of Ophiuride. 
Verrill, although, in relation to the hitherto described species 
of that genus, it isa giant. It differs only in the fewness of 
hooks or prongs with which the arm-spines of all the species 
are provided ; and the upper surface of the disk and arms 
displays a much finer granulation. 
This species also shows some affinity with Ophiogymna_ of 
Ljungman, judging from the brief and insufficient description 
of that author. The armature of the mouth is similar, the 
oral and adoral shields have the same position, and neither 
exhibit a tentacle-scale; but the radial shields in Ophiogymna 
are almost entirely covered with the soft skin enveloping the 
disk, whereas in the present species they are altogether naked 
as in Ophiothela. The arms are said to be very long by 
Ljungman ; but his description does not inform us regarding 
the plates, whether they are naked or covered with skin, 
smooth or granulated. Ophiocnemis of Miller and Troschel 
agrees with this species in the parts of the mouth, but differs 
in the arms, arm-spines, and covering of the disk. 
Ophiothela Holdsworthii, sp. nov. 
Disk circular, moderately thick, clothed with a soft skin 
beneath and above, except on the large radial shields; the 
latter are very remarkable on account of a raised keel or 
ridge, which extends from the inner or narrow end of the 
shield almost to the outer extremity, where it is most elevated, 
and terminates in a prominent angle; the shields are large, 
elongate, subtriangular, adjacent along the inner margins, 
except at the end, where they are slightly separated, leaving 
a notch between for the origin or insertion of the arm; they 
do not reach quite to the centre of the disk; and the inter- 
radial naked space between the different pairs is about equal 
in extent to one of the shields. Oral shields indistinct, small, 
somewhat triangular, with an angle towards the mouth 
between the small irregularly oval adoral scuta; teeth about 
three in number, irregular, small, acute at the end; tooth- 
apille in two series, irregular, not numerous. Arms 5, three 
and a half times as long as the diameter of the disk, slender : 
lower arm-plates, with the exception of a few near the oral 
end, clothed with a thin skin, and consequently rather indi- 
stinct; they appear to be very small, about as long as broad, 
outer and imner edges arched, the lateral margins very 
slightly convex; the first plates are situated between the 
adoral shields, are of the same size, and with them form a 
continuous ring around the mouth: upper arm-plates naked, 
minutely granulated, two or three times as broad as long, 
frequently fractured into two or more pieces, and hence more 
