old and new Amphipoda. 207 
The definition which he gave of the genus was so compre- 
hensive, therefore, as to be practically no definition at all. 
As five of his species could not fail to be distributed among 
the genera Aora, Microdeutopus, Gammaropsis, and Proto- 
medeia, the only one left to be the type of the new genus was 
that which he calls Awtonoé longipes (Lilljeborg). The 
minutely accurate observation of Sars distinguishes this by 
some rather small differences from the Lembos Websterii of 
Spence Bate, which Della Valle considers to be a synonym 
of it. The last-named author recognizes the inadequacy of 
the definitions given both by Bate and Bruzelius, but assigns 
the preference to the name Autonoé, because in 1870 it was 
redefined satisfactorily by Boeck. This is introducing into 
the rules of nomenclature a new principle which might lead 
to much confusion. Awtonoé having become a synonym of 
the earlier Lembos, it was not open to Boeck to make a choice 
between the two. His reagon for giving the preference to 
Autonoé may have rested on a misapprehension that Lembos 
had lapsed as a synonym of Microdeutopus, an error in which 
he has been followed by several writers. The genus Lembos 
will now contain the species Websteri’, Bate, longipes (Lillje- 
borg), megacheir (Sars), arcticus (Hansen), spiniventris 
(Della Valle), philacantha and kerguelent from the ‘ Chal- 
lenger’ expedition, possibly, as Sars has suggested, tenuis 
(Dana), and, lastly, a new species to be presently described. 
Lembos hirsutipes, sp. n. (Pls. VIII. & IX. B.) 
The first side-plates in the male subacutely produced, sub- 
rhomboidal in the female. The third pleon-segment with 
the postero-lateral angles scarcely rounded. 
The eyes are small. The first antenne have a rather long 
and stout first joint, the remainder being broken off in all the 
specimens. In the second antenne the third Joint is less than 
once and a half as long as it is deep, much deeper than the 
fourth joint, which is as long as the first of the upper pair ; 
the fifth joint is a little shorter than the fourth. The flagellum 
of four or five joints scarcely equals the length of the fifth 
joint of the peduncle. The mouth-organs do not appear to 
offer any distinctive features. 
First Gnathopod.—In the male the second joint is broad, 
with a brush of very long sete at the distal end of the 
hind margin, as in Lembos longipes (Lilljeborg) ; the small 
third joint has distally a transverse row of sete, the fourth 
has two small groups on the hind margin, and the fifth has 
three. The fifth joint or wrist is considerably shorter than 
Gi 
