REPORT ON THE AMPHIPODA. 1389 



setules, and having a spinule on the apex attended by one or two smaller ones just below 

 it ; the outer plates narrow, more than half the length of the joint on which they stand, 

 having three or four little spinules on the inner margin, one at the apex, and one just 

 below it on the outer margin. 



Triturating Organs. — As observed in the female, these are ovate with about thirteen 

 spines round one side, the largest spines standing a little apart from the rest, which are 

 graduated, diminishing in size as they retire from the largest. 



First Gnathopods. — The upper boundary of the side-plates could not be distinguished, 

 nor is it veiy clear in any of the segments. The first joint scarcely so long as the four 

 following together, widening immediately below the neck with a considerable bulge of 

 the front margin, below which it retains a breadth greater than that of the following joints; 

 the second broader than long, with a spine at the hinder apex ; the third a little longer 

 but not broader than the second, its distal margin projecting behind the wrist and 

 carrying two spines ; the wrist broader but shorter than the hand, with a spine at the 

 apex of the convex front margin, two on the straight hind margin, and one on and two 

 within the slightly produced apex, which projects behind the hand ; the hand has a spine 

 some way above the apex, planted a little within the convex front margin, the hind 

 margin straight, pectinate, and the distal margin minutely pectinate ; the finger curved, 

 more than half the length of the hand, at least half of the inner margin pectinate. 



Second Gnathopods. — Branchial vesicles as long as the first joint and at the middle 

 broader. The first joint with the front margin nearly straight, the hinder convex ; the 

 second joint with one spine at the hinder apex ; the third joint with six spines set about 

 its distal border ; the wrist longer than the hand, being more produced than in the first 

 gnathopods, with one spine at the apex of the front margin, one near the apex of the hind 

 margin, and one on and several within it ; the hand and finger as in the first gnathopods. 



First Per&opods. — Branchial vesicles like the preceding pair. First joint widening 

 from a narrow bent neck, the front margin then being straight and the hinder 

 convex ; the second joint longer than broad ; the third joint shorter than the fourth, 

 with a small spine at the apex of the hind margin ; the fourth joint shorter than the 

 fifth, the front margin convex, the hinder straight, loosely pectinate, with a spine at the 

 apex ; the fifth joint rather more closely pectinate ; the finger slender, curved, more 

 than half the length of the fifth joint, loosely pectinate along nearly half the inner 

 margin. 



Second Perseopods scarcely differing from the first, but with the fifth joint rather 

 shorter. 



Third Perieopods. — Branchial vesicles similar to the preceding pairs. First joint a 

 little dilated, especially below, the hind margin nearly straight, the front convex, pro- 

 duced lower than the hinder, having two little spines, one above, the other below, the 

 middle, and the distal part pectinate ; the third joint shorter than the fourth, each with 



