OPHIUKANS OF UNITED STATES NATIONAL MUSEUM. 13 



There is no doubt that this species, which I must consider as a new one, is 

 identical with the OphioglypJta indicated b}- Lyman ■ in 1S83, who rcfoired it, 

 together with other sj)ecimens, to 0. convexa, and wliich came from the dredgings 

 of the Blake in the West Indies. Here is what Lyman wrote about tliese specimens: 



The sbc primary plates extremely swollen, form an elevated njsette, overhanging \ery small radial 

 shields, not s<j large as the head of the genital scale. The mouth shield, too, occupies the vhole of the 

 lower interbrachial space. But specimens from station 148 were intermediate, or rather differed from 

 the tyjncal form only in finer arm comb pai)ill8e and more interbrachial scales on the disk margin. It 

 will be necessary to await further dredgings before deciding tlie specific limit.s. It is to be noted as an 

 important difference, that, while the tv-jjical 0. convexa is found in 2,350 fathoms, this species does 

 not go below 240 fathoms. 



I find again, in tlie collection of the Ophiurans of the Albatross, two specimens 

 wliich offer precisely the same pecuharities as Lyman indicated in 1SS3; it seems 

 to me obvious that these two examples can not be referred to 0. convexa, but that 

 they must constitute a dift'erent species the characters of which it is necessary to 

 describe. The disk is pentagonal and even slightly excavated in the interrailial 

 spaces; it is thick, but the upper face is httle convex; the under face is plane. 

 Tlie arms, rather short, grow rapidly thinner from the base which, besides, is not 

 verj' wide. 



The upper face of the disk is mostly occupied by sLx large polygonal plates, 

 contiguous and subequal, arranged as in 0. convexa, but tlie part of the disk covered 

 by them is still larger than in the latter species. Out of this primary rosette • 

 there is to be seen, in each interradial space, but one single largo plate, pentagonal, 

 somewliat longer than wide, with a proximal angle widely opened and a distal 

 side lying very close to the outhne of the disk; in fact, out of that plate is seen 

 only one other plate wliich is extremely sliort and transversally widened. On each 

 side of the large interradial jilato, and in its distal region, there are two or three 

 extremely small plates continued on the sides of the marginal plate which 

 succeeds the above-mentioned interradial plate. The radial spaces are entirely 

 occujiied by tlie two radial shields which are in contact with the corresponding 

 priniaiy radial plate, but are much smaller than the latter. 



These shields are a little wider than long; the two in each pair are con- 

 tiguous on their whole length and they form distally an extremely obtuse angle 

 into which is inserted the corresponding angle of the first upper brachial plate. 

 All the plates of the upper face of the disk are covered with pretty fine, rounded 

 granules, which shoot from the angles of a polygonal netting which covers the 

 plates and separates small rounded facets. The radial papil'te, visible on the 

 upper face, arc extremely elongated and closely disposed, numerous, fine, and 

 sharp; they become rapidly shorter on the under face, and do not extend beyond 

 the level of the distal third of the mouth shield. 



The under face of the disk, in the interradial spaces, is not very wide owing 

 to the widening of the arms at their bases; it is not completely covered by the 

 mouth shields, out of which is left a small space covered by a few jiolygonal and 

 unequal plates, among which one may be seen occupying a more or less exactly 

 median place, wliich is a little larger than the others. The genital plates are fairly 



I Bull. Mus. romp. Zool., vol. 10, p. 243. 



