REPORT ON THE AMPHIPODA. 1305 



broad, the second joint shorter and narrower, longer on one side than on the other, the 

 third joint nearly as long as the first two together, the apical margin on one side deeply 

 emarginate ; the first joint of the flagellum abruptly narrower than the last of the peduncle, 

 widest near the base, longer than any of the five following joints, which are rather stouter 

 than those of the upper antennae, similiarly ciliated. In a complete antenna the joints of 

 the flagellum are more than twenty in number. 



Upper Lip deeper than broad, unequally bilobed by a rather deep incision of the 

 distal margin. 



Mandibles with the trunk broad, especially at the base, narrower distally, the upper 

 front angle forming a small rounded lobe looking like the basal joint of the palp ; 

 below and just in front of this is another rounded angle, from which the margin descends 

 to the small cutting plate, the edge of which is divided into ten little teeth ; the 

 secondary plate of the left mandible is similar to the principal, and of nearly equal size ; 

 behind these there is a strongly ciliated or spinulose tract; the molar tubercle is 

 prominent, with broad crown carrying the usual long rows of denticles and cilia ; the 

 first joint of the palp is shorter but broader than the second, with the hind margin 

 convex till near the apex, the apical margin oblique ; the second joint is shorter than the 

 third ; the third is long, tapering to an extremely fine point, the almost straight front 

 margin having the adpressed cilia projecting conspicuously beyond it. The lobe of the 

 trunk which gives a four-jointed appearance to the palp is not separated at the base from 

 the body of the trunk. 



Lower Lip short, the front lobes wide apart, smooth ; the mandibular processes 

 broadly rounded, as large as the front lobes. 



First Maxillse. — No distinct inner plate ; the outer plate broad, strongly ciliated or 

 spinulose, and distally carrying five unequal spines, none of which are long, though two 

 are very stout ; the palp longer but scarcely broader than the adjoining plate, with a 

 noticeable spine at the apex of the inner margin, the apical and the distal half of the 

 very convex outer margin being scabrous. 



Second Maxillas. — Both plates with the usual armature of slender cilia-like spines, 

 the outer plate the longer, with two stronger spines on its narrow truncate apex, the 

 inner plate having one such spine on, and one a little below, the apex. 



Maxillipeds. — Second joint broad at the base, with a central ridge of the inner 

 surface leading up to the strongly spinulose inner plate, which rises above the distal 

 margin of the joint, and has one strong apical spine ; the outer plates small compared 

 with the joint on which they stand, the inner margin of one plate (in the specimen 

 examined) not armed exactly like that of the other, in each a few little spines and 

 spinules on and near the inner margin and the narrow but obliquely truncate apex, below 

 which there is a little furring of the outer margin. 



First Gnathopods. — Side-plates here as in the following pairs with the upper boundary 



