REPOKT ON THE AMPHIPODA. 1367 



projection for the opening of the duct ; of the three joints of the peduncle which follow, 

 the first is the stoutest, the second the shortest, the third about equal in length to the 

 first ; the flagellum is nine-jointed, not linear, shorter than that of the upper antennae, 

 but in stoutness equal to its terminal portion, the first joint far the longest, longer than 

 the peduncle, the other joints a little longer than broad. 



Gnathopods. — These agree, certainly in all essential details, with those of specimen A. 

 In the female I was able to perceive that the inner edge of the dactyloptera had a fine 

 pectination, a character which may probably belong to all the specimens, though some- 

 times eluding observation. 



First and Second Perseopods as in specimen A. 



Third Pereeopods. — First joint not greatly widened, with five teeth along the front- 

 margin, and two besides the apical teeth on the hind margin ; the second joint only 

 having the apical tooth of the front margin ; the third joint with two teeth to the front 

 margin ; the fourth joint having in one limb the longest tooth the fourth, in the other 

 limb the fifth on the front margin ; the fifth joint scarcely so long compared with the 

 fourth as in specimen A, so that the long tooth of the fourth joint would impinge below 

 the middle of the upturned fifth joint. 



Fourth and Fifth Perseopods. — The first joint with the front and hind margins 

 almost parallel, much narrower than in specimen A. 



Pleopods. — Peduncles long-oval ; the cleft spine not so stout as in specimen A. 



Uropods. — Second pair with only one ramus. 



Length. — Three-tenths of an inch, exclusive of the antennte. 



Female. — In all parts much more elongate than the male. 



Mandibles. — The trunk widest at the base, the cutting edge almost in line with the 

 long narrow body of the trunk and almost as wide, its margin apparently smooth, 

 though the surface just within it is closely striated as if leading up to a denticulate edge ; 

 the upper corner forms a shallow projection rather than a tooth, but the lower corner 

 presents at least one sharp upturned denticle, to the rear of which the lower margin is 

 ciliated ; the left mandible has a secondary plate, about half the width of the principal 

 plate, with its distal margin cut into about a dozen little teeth ; the molar tubercle 

 appears to be almost laminar, its broad distal margin partially projecting below the 

 body of the mandible, set with numerous little sharp teeth and ciliated ; the upper 

 border of the trunk, of which no part is free, is nearly straight, without palp or process. 



First, Maxillae. — The outer plate with some slender cilia and one or two that are more 

 spine-like projecting from the inner margin ; the oblique distal margin has four spine- 

 teeth rather wide apart, followed by two that are larger and stouter near the outer apex 

 and close beside these a smaller one at the apex ; the one-jointed palp over-arches the 

 outer plate, and has some very small spine-teeth on its distal margin. 



