1898-1902. No. 13.] ECHINODERMATA. 17 



broader brachial ventral plates and several tentacular papillse. Ophiura 

 albida, as we know, has normally only one papilla, though in rare 

 instances the innermost tentacle-pores have two. In this specimen, on 

 the contrary, there were from 2 to 4 papilte. 



The disc of the specimen is 24.5 mm. in diameter. The arms have 

 probably been about 100 mm. in length; but an accurate measurement 

 cannot be given, as large or small pieces of the points of the arms are 

 wanting. The abactinal side of the disc is covered with numerous irregular 

 scales, resembling those in Ophiura sarsi. The radial shields are pear- 

 shaped or oval, with the broader end turned outwards towards the margin 

 of the disc, the narrower end inwards towards the centre. They are 

 from 6 to 7.5 mm. long, and from 3 to 3.5 mm. broad, their length 

 being thus double their width. The arm-notches are from 1 to 1.5 mm. 

 deep, and are obtuse-angled ; and they are occupied by 2 or 3 dorsal 

 arm-plates. There are a few rudimentary papillse at only two of the 

 notches, while on the other hand, the remaining notches are altogether 

 without combs The bursal slits begin at the mouth-shields, and extend 

 to the margin of the disc. Their margin is altogether without papillse. 

 The interbrachial parts of the actinal surface of the disc are covered 

 with .scales similar to those on the abactinal surface. 



As in Ophiura sarsi, the mouth-shields are scutiform, their length 

 being greater than their width (3.5 mm. long, 3 mm. broad). Their 

 distance from the margin of the disc is about 5 mm. The lateral 

 mouth plates are quite narrow. There are 5 or 6 cuneate oral papillae, 

 the largest of which are above the teeth. These papillse are connected 

 with the papillse on the ab-radial margin of the first tentacle-pore, just as 

 in the Ophiura (Ophioglypha) maculata from the Bering Sea, described 

 by LuDWiG (21, p. 283). On both the ab-radial and the ad-radial margin 

 of the first tentacle-pore, there are from 4 to 6 flattened papillae. 



The arm-plates resemble those in Ophiura sarsi. The innermost 

 ventral arm-plates are twice as broad as they are long, and are separated 

 by only an exceedingly narrow space. Out towards the point of the 

 arms, the lateral plates increase in size, thus making the distance be- 

 tween the ventral plates greater and greater. At the same time the 

 latter also decrease in size. The lateral plates are furnished with three 

 robust spines o£ equal length, which do not extend beyond those plates. 

 The tentacle-pores within the margin of the disc have 3 or 4 flattened 

 papillse; and in the nearest of those outside the margin of the disc, there 

 are 3 papillse, or, in exceptional cases, 4. Farther out on the arms the 

 number of papillae is two, and towards their points there is only one. 



