130 GAMMARIDJl. 



of which is fixed below the apex of the plate ; the third 

 joint is likewise formed into a squamiform plate, much 

 smaller and more rounded than the preceding, and fur- 

 nished at the apex with a few plumose hairs. The arms 

 are long and slender, and differ but little from each 

 other. They are very imperfectly subchelate. The 

 first pair are rather the more robust of the two ; the 

 hand is much shorter, and has the inferior margin more 

 convex ; the palm is very oblique, and not defined ; 

 throughout the whole of the inferior margin, including 

 the palm, the joint is furnished with fasciculi, or rather, 

 short rows of hairs, most of which are short and simple ; 

 but there exists one or two in each fasciculus much 

 longer than the rest, straight and plumose : the wrist 

 is longer than the palm, and has the inferior margin 

 furnished with several short transverse rows of simple 

 hairs : the finger is half the length of the hand, and 

 is tipped with an unguis or nail, and armed upon the 

 inner side with three or four strong spines, furnished 

 with a serrated or spinous edge. The second pair of 

 arms are rather longer than the first : the wrist is fur- 

 nished with long plumose hairs, planted in short trans- 

 verse rows, laterally to the inferior margin ; the hand is 

 long, and of nearly equal breadth throughout, without 

 any distinguishable palm, the inferior margin is fur- 

 nished with several short transverse rows of simple and 

 plumose hairs ; the finger is but one-fourth the length of 

 the hand, it is unguiculate, and has the inner margin 

 armed with five or six small spines. The third and 

 fourth pairs of legs resemble each other, and differ in 

 form from those of other Amphipoda, the fourth joint 

 being long and broad, making a long ellipse, convex 

 upon the outer, and flat upon the inner surface, and 



