OF THE MERGUI ARCHIPELAGO. 



87 



large and symmetrical plates ; the rest of the plates diminish in 

 size from the margin to the mouth-shields ; and there is a row of 

 irregularly-shaped scales between them. 



Two generative slits, and the scale apparently divided into 

 three parts. 



Mouth-shields small, ovoid, narrowest externally, and with a 

 small accessory piece between the mouth-shield and the junc- 

 tion of the side mouth-shields. Side mouth-shields each nearly 

 as large as the mouth-shield, situated obliquely, and with the 

 inner point of junction far internal to the accessory piece, tri- 

 angular, and largest at the side, where they are in contact with the 

 first lower arm-plate, the first side arm-plate, and the mouth- 

 shield. Jaw-plate angles broad and long. Mouth-papilla? mostly 

 projecting downwards, irregular from the intercalation of accessory 

 papillae ; there are 13 in one angle, and 11 and 12 in the rest. 

 There may or may not be a papilla below the teeth, which are 

 stout and blunt, except the lowest, which is pointed. A long 

 papilla, which is in contact with the side mouth-shield and also 

 with the first arm -plate, is large and triangular, and might 

 be called a tentacle- scale. The accessory pieces are small and 

 resemble mouth-papillse. 



First lower arm-plate small, triangular, pointed within. The 

 next is very large and is broader than any other, broader than 

 long, straight where in contact with the first plate, slightly convex 

 externally, and with a re-entering curve on either side of the 

 straight part ; incurved for the tentacle at the part of the side 

 nearest the first plate, and more slantingly incurved further out for 

 the side arm-plate. Beyond the disk the plates are as long as 

 broad, slightly convex without and concave within, with re-entering 

 curves on either side and a straight border for the side arm-plate. 

 Far out they are separated by the side plates, and are triangular, 

 the angle being towards the disk. 



Upper arm-plates small, short, and moderately broad, not 

 extending across the arm, the usual space at the side being occu- 

 pied by a triangular accessory plate which reaches the side arm- 

 plate ; the surface of the upper plate is a nodular broad ridge 

 with a blunt point at the median line. Side arm-plates large, 

 tumid, but close to the arm, gradually having the accessory piece 

 between them, and crossing the upper surface of the arm close to 

 the tip. There are two close, flap-like tentacle-scales, and from 

 four to six, usually four, very small spines placed close to the 



