PROTOMEDEIA.. 
297 
AMPHIPODA. 
NATAT0R1A , 
GA MM A RIDES. 
Genus— PROTOMEDEIA. 
Protomedeia. Kroyek, Tidskr. iv. p. 154. 
Leptocheirus. Zaddach, Syn. Crust. Prussicorum Prodomus, p. 7, 
Ptilocheirus. Stimpson, Mar. Invert, of Grand Manan, p. 55. 
Generic character. Like Microdeutopus, but having the 
second pair of gnathopoda not subchelate. 
This genus is probably too closely associated with the 
preceding. But the form of the second pair of legs 
offers a similar ground of distinction as that which 
separates Talitrus from Orchestia. The coxae, moreover, 
appear to be rather deeper in this genus than in 
Microdeutopus; and the last pair of legs are not so 
proportionally long as compared with the sixth pair. 
The last pair of caudal appendages are double branched. 
We are uncertain as to the character of the central 
caudal plate since most of the specimens we have had 
an opportunity to examine have been more or less im- 
perfect, but in P. Whitei it appeared to be double, whilst 
Zaddach defines it as being sub-membranous and rounded 
above. 
The animals of this genus, though not abundant, 
appear to be widely distributed in the colder regions ; 
specimens being taken on the northern coast of the 
United States of America, on the coast of Scotland, in 
the Baltic, and oft’ the shores of the Crimea. 
