Rev. A. M. Norman’s Notes on British Amphipoda. 125 
such a situation that it can be seen (as in Barrois’s figured 
specimen) when the hand is viewed from the outside, and 
Costa’s figure might very fairly represent the external aspect 
of the hand of such an example as that figured here as fig. 4, 
provided the tubercle (c) was not quite so prominent. ‘The 
tubercle (4) is present in all three specimens and is tipped 
with short blunt spines; but the tubercle (c) is not developed 
in fig. 3; is small in the next size (fig. 4), but is largely 
developed in the most mature form (fig. 5). 
A comparison of these figures with each other and with 
those given by other authors will show that there must be 
considerable latitude allowed for variation in the exact arma- 
ture of this limb; the finger increases in comparative length 
with age and is more strongly bent in the younger specimens 
than in the mature. 
The hand of the second gnathopods (Pl. XI. fig. 2) in the 
female is more regularly ovate, the finger closes on the inner 
face, but there is no groove, the finger impinging against a 
few spines on the surface. 
The species is readily known from other British Amphi- 
pods by the characters of the telson (fig. 8), the remarkable 
last uropods (fig. 7), and the broadly expanded joints of the 
hinder perzopods (fig. 6). 
Stebbing has described two more species of this genus in 
the ‘Challenger’ Report. The £. subcartnatus, Haswell, 
may at once be distinguished by the very different telson, and 
HE. delaplata, Stebbing, by the difference in the last uropods, 
The general form of the second gnathopod is remarkably alike 
in the three species. 
The illustrations of this species are to many scales of 
enlargement. The pereopod (fig. 6) is the least magnified ; 
the illustrations of second gnathopods (3) (figs. 3, 4, 5) are 
more magnified; those of the gnathopods of female and of 
last uropods (figs. 1, 2, 7) are more magnified than the last, 
and the telson (fig. 8) is the most enlarged of all. 
Genus V. Mara, Leach, 1814. 
(= Megamera, Bate, Ceradocus, Costa, and Leptothoé, Stimpson.) 
1. Mera othonis (A. Milne- Edwards). 
1880. Gammarus othonis, H. Milne-Edwards, Ann. des Se. Nat. vol. xx. 
Pp; O(5;| Plax dig lI 2 
1847. Gammarus longimanus (Leach, MS.), Wm. Thompson, Ann, & 
Mag. Nat. Hist. ser. 1, vol. xx. p. 242, ¢. 
1847. Ganmarus elongatus, Frey and Leuckart, Beitr. zur Kennt. 
withell. Thiere, p. 160. 
