APPENDIX, 515 
AMPHIPODA, GAMMARIDES, 
NATATORIA. Vol. I. p. 410,*) 

MEGAMGRA MULTIDENTATA. (Norman MSS.) 
Specific character. Body long and slender. Second segment of pleon with 
three teeth on the middle of the posterior margin ; third segment with four; 
fourth, fifth, and sixth segments with two similar teeth. 
Length, six-tenths of an inch, 
Tue body is long and slender, with the segments subequal ; 
the second segment of the pleon having a central, and on 
each side a lateral tooth on the posterior dorsal margin; third 
having a central and two lateral teeth on the dorsal margin ; 
the three following segments without a central, but possessing 
on each a lateral tooth, at the base of which a strong hair or 
spine exists. 
The eyes are round and black. The superior antenne are 
half the length of the animal, and the peduncle is half the 
length of the antennse. The first joint is as long as the 
cephalon ; the second joint is a little longer and slighter than 
the first; the third is short. The articuli of the flagellum 
are as long again as broad ; the secondary appendage consists 
of five articuli. The inferior antenne are about half the length 
of the superior; the peduncle extends to the extremity of the 
second joint of the peduncle of the superior. Olfactory denticle 
LL 2 
