226 BULLETIN OF THE 



(4th plate) 1.4 : 1.4. The first plate is minute, being nearly crowded out by 

 the side mouth-shields. Side arm-plates forming only a small ridge for the 

 arm-spines. Upper arm-plates hexagonal, with the outer and inner sides 

 'shorter than the others; length to breadth 1.4:2. Skin of disk quite 

 smooth, above and below. Arm-spines three, cylindrical, stout, gently 

 tapering, blunt; lengths to that of upper arm-plate (7th joint) 5. 3, 2.7 : 1.4. 

 They are essentially smooth, although, under the microscope, the points look 

 minutely thorny. One huge, tentacle-scale, longer than broad, and ilat. 

 Ground-color of disk and upper arms purplish brown. Disk, above and be- 

 low, ornamented with patterns in dark brown lines. Above, there are 

 straight lines from arms to centre, and, in interbrachial spaces, above and 

 below, meandrine patterns, which are tilled with white, yellowish, or purplish 

 brown. A dark stripe along upper arm; arm-spines with three to five dark 

 rings. 



The original specimen of Miiller and Troschel at Leyden, brought from 

 Java by Kuhl and Van Ilasselt, remained for a long time a unique speci- 

 men. Within a few years the Leyden Museum has obtained others from 

 islands near New Guinea, and Professor Semper also got very fine ones from 

 the Philippines and the Pelews. This species, by its well-marked upper 

 arm-plates and regular arm-spines, approaches nearer than 0. elegans to the 

 genus Opldocoma, from which it differs only by its naked disk. 



Ophiomastix flaceida sp. nov. 



I'late VI., Tigs. 14, 15. 



Special Marl?. — Xo tentacle-scales. l>isk smooth, except a few short 

 spines above. Upper and side arm-plates obscured by thick skin. 



Description of an Individual. — Diameter of disk 15 mm. Length of arm 

 100 mm. "Width of arm 3 nun. Height of arm 2 nun. Distance from 

 outer side of mouth-shield to inner points of tooth-papilla?, compared with 

 that between outer corners of mouth-slits, 3 : 2.5. Mouth-papilla? four on 

 each side, small and bead-like, except the outer one. which is pointed. 

 Tooth-papilla? similar, usually nine, arranged in three regular rows, of which 

 the lowest is on a level with the mouth-papilla?. Teeth five or six, the 

 tipper ones longest, with a square cutting edge ; the lowermost smaller and 

 rounded, or partly split. Mouth-shields small, of a much rounded heart- 

 shape, length to breadth 2 : 1.8. They are close against the outer mouth- 

 papilla?, leaving little space for the minute side mouth-shields, which do not 

 meet within, and are obscured by thick skin. Under arm-plates squarish, 

 with rounded corner.-; length to breadth 1.5 : 1.5. Side arm-plates obscured 

 by thick skin, as also are the upper one-, except in dry specimen-, where 

 their form is seen to be rounded hexagonal. Disk wholly covered by smooth 



