AMPHIPODA. 27 
edges dentate ; spine row long, of about twenty spines; the palp, which is set on in 
front of the middle, is longer than the mandible; the first joint about one-third as 
long as the second, which is subequal to the third. One of the mandibles appears to 
be without a secondary cutting plate. 
First maxille: Inner plate with about 12 plumose setze on its inner margin. 
First gnathopods : First joint stout, rather longer than the side-plate, and subequal 
to the wrist and hand united ; these are subequal to each other, the wrist rather the 
wider ; the hand is oval, the palm undefined, pectinate ; the whole hind margin sparsely 
and unequally spinous. Dactylus with 5 spines on the inner margin. 
Second gnathopods are like the first, except the palm, which is more transverse, and 
about half as long as the rest of the hind margin. 
Second perxopods : Side-plates reaching below the second joint. First joint narrow, 
oblong, subequal to the third and fourth united; third rather longer than the fourth, 
and shorter than the fifth. Dactylus continuous with the fifth joint, as long as the 
third, and slightly curved. 
Third and fourth pereeopods subequal: First joint oblong, twice as long as wide ; 
third joint half as long as the first, acutely produced behind ; fourth joint subequal to, 
and fifth rather longer than the first. Dactylus very long, about one-fifth longer 
than the fifth joint, and tapering very gradually. These two pairs appear to be 
generally carried elevated over the back. In the largest specimen (25 mm.) the 
dactyli are not quite so long relatively. 
Fifth perzopods are considerably shorter, and the first joint wider, than the third 
and fourth; hind margin of the first joint convex, obscurely serrate, and produced 
downwards in a rounded lobe almost to the middle of the third joint; this is 
much produced behind, and is a little shorter than the fourth, which is as long as the 
dactylus and shorter than the fifth joint. 
First and second uropods: The rami longer than the peduncles, the outer shorter 
and narrower than the inner. 
Third uropods: Rami nearly twice as long as the peduncle, subequal, the outer 
the narrower, with fine spines on both margins. 
Telson, reaching to about one-fourth the length of the rami of the third uropods, 
deeply notched at the end, with a minute notch on the tip of each division. 
The above description, with the exception of that of the external characters of the 
animal as seen without dissection, is taken from a young specimen 6 mm. long. 
FAM. IPHIMEDIID®, Sreserne. 
IPHIMEDIA PACIFICA. 
Iphimedia pacifica, Stebbing. 
W.Q., 20 Feb. 1902, 20 fm., one; 14 Jan., 1903, 130 fm., one, young, about 
8mm.; 14 July, 1903, 130 fm. one, length 24 mm.; 30 Sept., 1903, one, length 
20 mm.; two on 4 Sept., 1905, one, length 30 mm. 
