230 BULLETIN OF THE 



One which was broken near the end was 145 mm. "Width of arm 1.3 mm. 

 Distance from outer side of mouth-shield to inner point of mouth-papilla* 

 compared with that between outer corners of mouth-slits 1.4 : 1.4. Mouth- 

 papillae four to each angle ; namely, two large wedge-shaped ones, just 

 under the teeth, and one, small and slender, sitting on each side mouth-shield. 

 Mouth-shields small, broader than long, nearly oval ; length to breadth 

 .5 :.7. Side mouth-shields curved and united at their ends so as to form 

 a continuous ring. Under arm-plates broader than long, squarish, with a 

 peak within and a re-entering angle without; length to breadth, within the 

 disk, .4 : .5. Side arm-plates nearly meeting above and making only a 

 slight ridge, on which stand the spines. Upper arm-plates irregular oval, 

 rather small, not covering the upper side of arm; length to breadth .4 : .7. 

 The plates next the disk are narrower and more irregular. Radial shields 

 long and narrow ; joined for about half their length, which is to their breadth 

 as 2 : .6. Their free sides are edged, with two or three parallel rows of 

 minute scales. The rest of the disk is puffed, deeply wrinkled, and quite 

 naked. Arm-spines on the basal and middle portions of the arm five, 

 of which four are short, cylindrical, and tapering; but the one next the 

 lowest is flattened, much thickened, and thorny at its end. Its length is 

 about .4 mm. No tentacle-scales. Color, in alcohol, brownish gray. 



The true OpMonephthys of Liitken, which includes but one species as yet 

 (0. limicola), has lines of fine scales not only round the radial shields, but 

 thence extending towards the centre of the disk and along its edges ; also 

 the mouth-papilla? may be' either four or six to each angle of the mouth. I 

 prefer, however, to leave the new species in this genus, because the groups 

 which centre about Amphiura are not yet very clearly established. 



One specimen from Philippines ; C. Semper. 



Ophiocnida echinata? 



Ophiophragmus ccldnatus 1 Ljungman. 

 Ophiocnida longipeda Lym. M. S. 

 Plate IV., Figs. 22, 23. 

 Special Marks. — Upper disk, and a triangular patch in each interbrachial 

 space below, beset with minute sharp spines. Radial shields narrow, wholly 

 separated, naked. Three arm-spines, except close to disk. Four mouth- 

 papilla? on each side. Arms very long. 



Description of an Individual. — Diameter of disk 10 mm. Length of arm 

 200 mm. Width of arm 2.2 mm. Four mouth-papilla? on each side, of which 

 the innermost is bead-like, the two next of about the same size but more 

 flattened, and the outer one smallest and tooth-like. Distance from outer 

 side of mouth-shield to inner point of mouth-papilla? to that between outer 



