REPORT ON THE AMPHIPODA. 1043 



being divided into three strong simple teeth ; on the third joint of the palp there are four 

 pairs of spines to the front margin and a pair on the apex. 



Lower lap. — The principal lobes broad, the distal margins broadly convex ; the inner 

 lobes rather tumid, distally well ciliated ; the mandibular processes small and little 

 prominent. 



First Maxillae. — Inner plate apically narrowed, and carrying on the apex two small 

 plumose spines or short setse, the outer a little longer than the inner ; the eleven spines 

 on the outer plate are not very dissimilar to those of Ampelisca acinaces; the inner ones 

 have lateral denticles instead of serrate edges, but possibly in the other species the 

 denticles have been worn or accidentally broken off; the second and third of the inner- 

 most have, however, in this species their concave inner edges smooth ; the palp has the 

 distal edge of the second joint cut into sharper teeth and bordered with sharper and 

 longer spine-teeth than in the other species ; there are eleven submarginal spines. 



Second MaxillsB. — Rather below the middle of the inner margin of the inner plate 

 begins a row of about thirteen long plumose seta?, which cross the surface a little below 

 the apex ; another row begins nearer to the apex, which itself is narrowed, sloping out- 

 wards, fringed with many long spines ; the inner plate is longer than the outer, wider 

 towards the apex, which has an outward sloping curve, and is fringed with very many 

 long spines. 



Maxillipeds resembbng those of Ampelisca acinaces, but with the distal margin of 

 the inner plates more squarely truncate ; the outer plates with nine spoon-shaped spine- 

 teeth on the inner border, and six spines on the broad indented distal margin, the two 

 outermost being plumose, setiform ; the second joint of the palp is long, crowded with 

 spines on the inner margin and apex, and also has a single spine on the outer margin 

 below the centre ; the third joint is widest not far from the base, and then narrows to 

 the broad flat apex, round which and the inner margin there are many spines ; the finger 

 is inserted far below the apex ; it is very narrow, and has a long thin nail which consti- 

 tutes nearly half its total length ; on the inner margin near the base of the nail it has 

 about four decurrent spinules ; the dorsal cilium is small, near the hinge. 



First Gnathopods like those of Ampelisca acinaces, differing as follows : — The side- 

 plates are much less widened below, the hind margin is straight with no concavity, 

 though it may be noticed that it has the little terminal tooth; the setae that project 

 below the lower margin are here less regularly set on the surface ; the second joint has 

 spines at two points of the hind margin above the apex ; the third joint has very 

 numerous spines along the hind margin, and a row which crosses the surface above the 

 apex ; there is a long row of long spines on the inner surface of the wrist ; the hand is a 

 little more dilated near the base, and the spines on the inner surface seem to be more 

 numerous than in the other species. 



Second Gnathopods. — Side-plates a little dilated below, the hind margin nearly 



