REPORT ON THE AMPHIPODA. 697 



first two joints of the leg ; third joint longer than fourth, shorter than fifth, wider than 

 either, a little outdrawn antero-distally, with three longer and two shorter setse on the 

 hind margin; fourth and fifth joints slender, with few setee, and one spinule at the 

 postero-distal angle of the fifth joint ; finger long and curved. 



Second Pereeopods. — Side-plates deeply excavate behind, deeper than their greatest 

 breadth ; branchiae on this pair, no doubt accidentally, very small. 



T/iiixl Perseopods. — Side-plate much larger than first joint of leg, only slightly bilobed, 

 hinder much less curved than anterior margin ; first joint subcircular, some cilia on lower 

 part of anterior margin ; second and third joints both considerably shorter than in the 

 two preceding pairs. 



Fourth Perssopods. — Side-plate squarish, smaller than first joint; the latter ovoid, 

 infero-posteriorly produced, ciliated in front ; the third joint wider, not longer than in 

 the preceding pair. 



Fifth Pcrieopods. — Side-plates smaller than the preceding pair, having like them a 

 minute infero-posterior notch ; first joint much broader and longer than in the preceding 

 pair, front margin naked except at the lower angle, hinder margin irregularly rounded, 

 crenulate, produced below\ The two next joints as in the preceding pair. The fourth 

 fifth, and sixth joints were missing from the last four pairs of perssopods. 



Pleopods.- — These are rather peculiar in structure The broad peduncle carries two 

 branches very differently shaped ; the outer branch has its first joint nearly as long as 

 the peduncle, very broad near the base, ciliated on the outer edge round the broadest 

 part, and wdth six plumose bristles along the lower part, increasing in length as they 

 approach the short second joint ; the third joint is narrower than the second ; the fourth, 

 much narrower and shorter than the third, concludes the series. They are furnished 

 with the usual long plumose setas. The inner branch has the first joint long and narrow, 

 together with the short second joint equalling the length of the first joint of the outer 

 branch, like which it has a third and fourth joint but no more ; in the third pair the 

 second joint is coalesced with the first. The two coupling spines are very small and 

 slender and appear to be quite straight. A single short bent spine at the distal end of 

 the first joint of the inner ramus seems to be the representative of the cleft spines. 



Uropods. — The first pair have the peduncle equal in length to the outer ramus ; the 

 inner ramus is a little shorter. On the peduncle there are three spines with accessor)' 

 threads near the tips ; there is one on the outer and probably also one on the inner 

 ramus. The second pair are shorter than the first ; the peduncle subequal in length to 

 the outer ramus, which is rather longer than the inner ; each ramus has one spine and the 

 inner edge finely pectinate. The third pair is much shorter than the second, the outer 

 ramus longer than the inner, and about as long as the peduncle, with a terminal nail so 

 large as almost to look like a second joint. On the inner ramus there is a ciliuni near 

 the base. The edges of both rami are like those of the second pair. 



(ZOOL. CHALL. EXP. — PART LXVn. — 1887.) Xxx 88 



