24 Mr. 1. C. Thompson on the Copepoda 
Metridia longa, Lubbock. 
1854. Calanus longus, Lubbock, Ann. & Mag. Nat. Hist. ser. 2, vol. xiv. 
p. 127. 
One of the commonest species in the collection. Found 
in thirty-three out of the forty bottles comprising the 
collection, at depths from 50 to 1770 fathoms. 
Metridia venusta, Giesbrecht. (Pl. VI. figs. 1, 2.) 
1889. Metridia venusta, Giesbrecht, Atti Acc. Lincei Rend. ser. 4, 
vol. v. p. 24. 
One specimen only, and fortunately a mature male, 
hitherto unknown, was taken at 1570 fathoms. ‘The general 
characters agree with those of the female as described by 
Giesbrecht, the anterior antennee and fifth pair of swimming- 
feet being the main differences between the sexes. 
The right anterior antenna is 26-jointed, the left 23- 
jointed, the latter being geniculated between the seventeenth 
and eighteenth joints ; both are very thin in the latter half. 
The proportionate lengths of the joints of the left antenna 
are as follows :— 
The fifth pair of feet (fig. 2) are very elaborate ; each is 
2-branched, the outer ones are 4-jointed and terminated by 
strong spines, the left spine being more than double the 
length of the right. The inner branch of each foot is 
3-jomted, each apical joint having two lateral and four 
terminal setz. A finely setiferous lateral lamella is attached 
to the basal joint of each foot. 
Giesbrecht’s specimens were from the Pacific; so the 
known range of the species is now widely extended. 
Metridia princeps, Giesbrecht. (Pl. VI. figs. 3, 4.) 
1889. Metridia princeps, Giesbrecht, Atti Acc. Lincei Rend. ser. 4, 
vol. v. p. 24. 
Three specimens of this large and well-marked species 
were found—one, fortunately a male, hitherto unknown, at 
1410 fathoms, and two females at 1610 fathoms. The 
important differences between the sexes, as with the last 
species, are in the anterior antenne and the fifth pair of 
swimming-feet. 
Male (fig. 3).—Length 650 millim, The right antenna 
