REPORT ON THE AMPHIPODA. 1297 



together, all three broader than long ; the first joint of the flagcllum considerably longer 

 than the peduncle, for some distance nearly as thick as the peduncle, then tapering 

 gradually, with a narrowed terminal piece more than a third, but less than half, the 

 length of the joint ; the second joint is minute, a little longer than broad, and in our 

 specimen this is the last. 



Lower Antennas in the present specimen straight and almost smooth, situated very 

 near one another ; the first free joint scarcely longer than broad, the second a little, and 

 the third a good deal, longer than the first ; the following joint, which is probably the 

 first of the flagellum, is nearly as long as the three preceding together and longer than 

 the two subequal terminal joints combined. 



Upper Lip. — The outer plate distally unsymmetrically bilobed with a not very deep 

 emargination, each lobe having fur directed towards the emargination ; the inner plate 

 has a slightly convex distal margin which is hairy. 



Mandibles. — The upper margin of the trunk behind the palp is straight ; the cutting 

 plate has about nine teeth, of which the lowest stands somewhat apart from the rest ; the 

 secondary plate of the left mandible has seven teeth very similar to those of the principal 

 plate ; on the right mandible it seems to be rather different, with one long tooth and the 

 rest slighter ; besides some ciliation above the plates there is a spine-row, with several 

 strong, more or less denticulate spines among others that are slender and hair-like ; the 

 molar tubercle is prominent, cylindrical, with strongly dentate crown, in general appear- 

 ance recalling the form common in the Gammarina ; the first joint of the palp is twice as 

 long as broad, but short compared with the other joints ; the second is between two and 

 three times as long as the first, longer and much broader than the third, narrowest at 

 the two extremities, a little bent near the lower end ; the long and narrow third joint 

 has some small spines or setules along the convex hind margin of the acute apex. 



Lower Lip. — Principal lobes rather broad, ciliated ; the rounded apices of the man- 

 dibular processes scarcely free. 



First Maxillae. — Inner plate small, oval, smooth ; the outer plate with numerous 

 slender spines of various lengths on the surface and margins ; the distal margin truncate, 

 carrying eight strong but unequal spines, most of them having one or two lateral 

 denticles ; the palp joint is strongly ciliated, its outer margin convex, the inner nearly 

 straight for more than half the distance from the base, the remainder concave, a spine 

 being placed at the junction of the two portions ; there are also some small spines on 

 and near the very narrow truncate apex. 



Second Maxillze. — The two plates appear to be coalesced into a single plate with two 

 apices, of which the inner is the larger and more prominent ; there are numerous hair-like 

 spines and slender spines about each apex, and a small spine at each apex. In the genus 

 Vibilia these two plates are seen to be partially coalesced, and here, if my observation is 

 correct, the coalescence is carried a step or two further. 



(ZOOL. CHALL. EXP. — PAET LXVII. 1888.) Xxx 163 



