1887.] G. M. Giles — Six new Amphipods from the Bay of Bengal. 223 



being stouter with its basipodite shorter than in the hinder ; they are 

 provided with a curious complex subchela (Fig. 7.). The dactylopo- 

 dite forms a stout sharp claw and is articulated to the propodite by 

 a movable joint acted on by powerful muscles. The propodite consists 

 of a stout cylindrical curved body so bent that its posterior border is 

 apposed to the prolonged inferior border of the carpopodite. This 

 posterior border is armed with a strong flat plate provided with a 

 toothed cutting edge. The carpopodite is stout, compressed, and 

 quadrangular, and has its infero-posterior angle prolonged into a sharp 

 process. The posterior half of this border is formed by a thin plate with 

 a toothed edge, opposable to the smaller plate on the propodite. In 

 extreme flexion, these two plates overlap each other, the carpopodital 

 plate passing inside that of the propodite ; all the remaining articula- 

 tions are compressed, but broad and strong, the meropodites are short 

 and triangular, the ischiopodites short and quadrangular. The basi- 

 podite of the 2nd gnathopoda is as long as all the other articulations 

 together, while that of the first is but f as long ; in both, the articu- 

 lations are curved forwards and extremely stout. A cord-like glandular 

 body runs through the middle of each of these appendages ending in 

 the base of the propodite. It is difficult to be certain as to the point of 

 exit of its duct, but this was doubtfully made out as opening near the 

 angle between the two limbs of the subchela. The muscles of these 

 appendages are large and distinct, each joint being provided with a 

 flexor and extensor ; in the two distal articulations, the flexor is by far 

 the more powerful, but in the next the two are nearly of equal strength, 

 while, of the muscles contained in the basipodite, the extensor is the 

 more powerful, and its tendon, passing through the ischiopodite, is 

 inserted into the base of the meropodite, being reinforced by only a 

 small slip taking origin from the former joint, while only a small 

 accessory slip of the extensor contained in the basipodite is inserted 

 into the ischiopodite. The 4th and 5tli thoracic appendages are cylin- 

 drical and of the usual ambulatory type ; they are subequal, slightly 

 exceeding the thorax in length, but the fifth is slightly the stouter of the 

 two. The 6th and 7th are like the two preceding appendages, save that 

 their basipodites are strengthened by strong buttress-like developments 

 of their anterior and posterior borders ; the 7th but little exceeds the 5th 

 in length ; but the 6th is the longest of all the thoracic appendages, equal- 

 ling the thorax and the first abdominal segment in length. The 8th tho- 

 racic appendage is peculiar, its basipodite is formed on the same plan as 

 those of the sixth and seventh, but is shorter, and if anything broader, so 

 that its outline approaches the circular, and its remaining joints are so 

 short that together they do not equal the breadth of the basipodite. 



