REPORT ON THE AMPHIPODA. 971 



Upper Lip. — The front margin rounded, the hairs at the centre standing out straight, 

 while those on either side converge towards them ; outside of the hairy tract arc spiny 

 cilia on either side, forming a curved band across the surface. In the figure J.s., the 

 inner plate is drawn protruding beyond the outer, not in its natural position. 



Mandibles. — The cutting plate on the left mandible forming a single tooth with a 

 strong, sharp, curved edge, bending round the secondary plate ; in the unworn condition 

 this edge has a triangular tooth lying upon it at the top, and is interrupted so as to form 

 a small tooth before reaching the apex ; the secondary plate has its margin divided into 

 five strong teeth ; on the right mandible the cutting plate has a strong process above, 

 and is apically divided into two teeth ; the secondary plate in profile appears to resemble 

 that on the left mandible, but to be slighter, and to have the upper teeth smaller ; the 

 spine-row is composed of six long, curved, denticulate spines ; the molar tubercle is 

 prominent, with a small sharply-toothed crown, of almost triangular outline, set about 

 with many cilia ; there is a blunt-headed process between the molar tubercle and the 

 palp ; the first joint of the palp is short, the second much shorter than the third, its 

 hind margin nearly straight, the front convex, with thirteen spines upon it or the 

 adjoining surface ; the third joint very long and narrow, with the hind margin smooth, 

 convex, the front margin except near the base closely fringed with spines, those near the 

 narrow apex of increased length. 



Lower Lip. — The rounded distal margins of the principal lobes lightly ciliated, the 

 inner margins dehiscent, each having near the top a projecting line of eight or ten 

 spines, the roots of which are grouped on the surface ; the rounded distal margins of the 

 short thick inner plates are closely furred ; the mandibular processes are short, apically 

 rounded ; their inner margin is continuous with a curved fold of the principal lobes, 

 which is strongly ciliated with spiny cilia, especially where it approaches the group of 

 spines above-mentioned. 



First Maxillae. — The inner plate much longer than broad, the apex sloping inwards 

 with two slender spines or short setee on the sinuous margin ; the outer plate with ten spines 

 on the truncate margin, the lateral teeth varying in number from two to seven on the 

 different spines, but in all long and slender ; the first joint of the palp more than half the 

 length of the second, with two spines on the outer margin ; the second joint with five 

 setiform spines on the outer margin, five on the narrow apex, and ten on the oblique 

 margin below it, which may be reckoned either as part of the apex or of the inner 

 margin ; there is one seta on the outer margin of the trunk below the palp. 



Seco?id Maxillx. — The inner plate as long as and a little broader than the outer, with 

 spines on the rounded distal margin and halfway down the inner margin ; the outer 

 plate with spines round the distal margin, the longest at the most advanced point, 

 followed by four shorter ones on the outer side, the outer border having three long 

 plumose setse on the upper half, and a short seta or spine below. 



