REPORT ON THE AMPHIPODA. 1453 



long as the fifth joint, slightly curved, of nearly uniform breadth till close to the apex, 

 which is prolonged by an almost setiform nail, with a setule on the inner side. 



First Perwopods stouter than the gnathopods, and longer, with smooth margins, the 

 first joint widening distally, the second rather longer than broad ; the third longer and 

 broader than the fourth ; the fifth joint slightly curved, a little longer than the third, with 

 an exceedingly minute pectination of the distal margin ; the finger small, with the base 

 much wider than the rest. 



Second Penvopods Hke the first, but longer, the third joint as long as the fifth. 

 Tldrd Per&opods. — Branchial vesicles oval, very small. First joint twice as long as 

 the branchial vesicles, rather narrowly oval, longer and considerably broader than the first 

 joint of the preceding pair, having minute submarginal setules along the front ; second 

 joint a little longer than broad ; third joint straight, narrow, longer than the first, fringed 

 with between twenty and thirty little submarginal setules along the front ; fourth joint 

 shorter and more slender than the third, similarly furnished, its length on one side of the 

 specimen longer than that of the first joint, on the other side shorter; fifth joint linear ; 

 armed along the front with distant microscopic spinules or setules ; the tip of the 

 narrowly tapering joint broken off, but the part remaining exceeding the length of the 

 long third joint. 



Fourth Perzeopods. — Branchial vesicles a little longer than in the preceding pair, 

 the limb shorter. The first joint longer than in the third perseopods and twice 

 as broad, with a few little setules along the front, which has an occasional mark of 

 serration, the most pronounced being at the apex ; the second joint not longer than 

 broad; the third joint nearly as broad as the first and not very much shorter, the hind 

 margin extremely convex, the apex broadly produced downwards, with some microscopic 

 pectination or furring of its margin, the front border with a slight serrature of six teeth 

 and the apex acute ; like the two following joints it has some tiny submarginal spinules 

 or setules ; the fourth joint much shorter than the third and little more than half the 

 breadth, the hind margin convex, the front cut into eight or more decurrent teeth ; the 

 fifth joint a little longer than the fourth, much narrower, the front margin cut into 

 fourteen decurrent teeth, the narrower apical border finely pectinate and having at the 

 back two produced teeth ; the finger small, tapering ; the tip broken. 



Fifth Perseopods slender, longer than the gnathopods. The first joint narrowest 

 distally, as long as the three following joints together, the muscles occupying a very 

 small part of the joint ; the second joint longer than broad ; the third slender, curved, 

 smooth like the rest of the limb ; the fourth rather longer than the third ; the fifth 

 shorter than the third ; the finger very small and crooked. 



Pleopods. — Peduncles stout, those of the first and second pairs longer than the rami ; 

 coupbng spines minute, round-headed, with only the apical pair of retroverted hooks ; 

 the cleft spine slender, rather sinuous, the two arms nearly equal ; the first joint of the 



