REPORT ON THE AMPHIPODA. 1053 



the third joint less than a fifth the length of the second, widening a little distally, with a 

 long but very slender terminal spine or seta ; the fiagellum much longer than the peduncle, 

 consisting of thirty-four slender joints, the lengths varying irregularly, some of the apical 

 setiform spines being of very great length. 



Lower Antenna?. — First and second joints short, the second apically pointed on the 

 side opposite to the short blunt gland-cone ; the third joint as long as the preceding two 

 united, its upper margin convex, the lower nearly straight ; the fourth joint slender, 

 longer than the second of the upper antennae, with long slender spines or setae on the 

 under margin ; the fifth joint shorter than the fourth, similarly furnished, as long as the 

 second joint of the upper antennae ; the fiagellum of eighteen slender joints, together 

 shorter than the peduncle, and shorter than the fiagellum of the upper antennae, apically 

 furnished with slender spines of various lengths. 



Upper Lip. — The outer plate with flattened sides, the distal margin semicircular, with 

 a little almost central emargination, on either side of which it is furred, the cilia as usual 

 directed from either side towards the centre ; the inner plate less advanced, its distal 

 outline similar but without any notch, the central part strongly furred. 



Mandibles. — The principal and secondary plates on the left mandible with five or six 

 teeth apiece, those on the right with the usual modifications ; the spine-row on the left 

 mandible having thirteen spines, close set, curving backwards, most strongly denticulate 

 near the apex ; on the right mandible there are only ten spines, and of these the inner- 

 most is linear ; the crown of the molar tubercle on the left mandible is almost pentagonal, 

 with small marginal teeth on two of the sides and some transverse ridges ; on the right 

 mandible it was only observed in profile ; the first joint of the palp is short, narrow at the 

 base, with a few small marginal spines ; the other two joints are as in Ampelisca chiltoni. 



Lower Lip. — The principal lobes broad, much cdiated, the inner lobes rather tumid ; 

 the mandibular processes Httle prominent. 



First Maxilla;. — The inner plate narrow, with two short setae on the apex ; the outer 

 plate broad, with the eleven spines on the broad distal margin like those of Ampelisca 

 chiltoni; there are spines at four points of the outer margin of the joint supporting this 

 plate ; the first joint of the palp is short, with a spine at the middle of the outer 

 margin ; the second joint is long, curved, expanding distally, the five teeth of the apical 

 margin small, and its five spine-teeth neither long nor broad ; there are seven slender 

 spines below the distal margin and seven fringing the convex outer margin. 



Second Maxillee like those of Ampelisca chiltoni. 



Maxillipcds closely resembling those of Ampelisca chiltoni ; on the outer plates, which 

 reach as nearly as possible as far as the long second joint of the palp, there are eighteen 

 to nineteen spines, ten or eleven belonging as spine-teeth to the inner margin, the rest to 

 the distal, the outermost four being setiform ; on the inner margin of the finger near the 

 nail there are some half-dozen spinules. 



