206 Rev. T. R. R. Stebbing on 
Our present concern is with that section of the Photide in 
which the first gnathopods are larger than the second, espe- 
cially in the male sex. 
In Aora the first gnathopod of the male has the fourth 
joint greatly produced, so as, in combination with the long 
finger, to make the limb complexly subchelate. 
In Microdeutopus it is the fifth joint, instead of the fourth, 
which is produced to meet the finger. 
In Stimpsonella (the name proposed by Della Valle for 
Spence Bate’s preoccupied Stempsonia) the first gnathopod 
agrees with that of Microdeutopus, but the second gnathopod 
has the prehensile angle of the sixth joint more or less pro- 
duced. Bate and Westwood (vol. i. p. 284) say :-—‘¢ This 
genus probably bears too close a resemblance to Microdeutopus 
to be retained as generically distinct.” Sars also (‘ Crus- 
tacea of Norway,’ p. 540) remarks that it is closely allied to 
Microdeutopus, “ and should, perhaps, more properly be com- 
bined with it.’ An opinion to the same effect is rather more 
decidedly expressed in the ‘ Challenger’ Amphipoda, p. 334. 
One is the more encouraged in regarding the character on 
which Stimpsonella is founded as of not more than specific 
value, because Della Valle distinguishes his own Autonoé 
spintventris from two other species of the same genus by the 
mark that it has the prehensile angle of the first gnathopods 
in the male not prolonged, whereas in the other two species it 
is prolonged into a spiniform process. It may be noticed 
that on page 400 of Della Valle’s work ‘‘ gnatopodi poste- 
riori”’ is merely a misprint for ‘ gnatopodi anteriori.” But 
in closely related forms a difference cannot consistently be 
given generic value in one gnathopod if it has only specific 
importance in the other. 
In Autonoé, as it is commonly called, the first gnathopods 
of the male are simply instead of complexly subchelate, there 
being no process either of the fourth or the fifth joint to meet 
the finger. Here, too, the sixth joint is as broad and as large 
as the fifth, which is far from being the case in Microdeutopus. 
As regards the name of the genus, it seems clear that the 
discarded Lembos ought to be restored. Under this name, 
published without description in 1856, a genus was instituted 
by Spence Bate in 1857 with four species, of which some 
indeed belong to the earlier Microdeutopus, but one of them, 
Lembos Websterti, has been referred alike by Boeck, Sars, and 
Della Valle to Autonoé. Now Autonoé was not instituted by 
Bruzelius before 1859. ‘To it he ascribed six species, two of 
which he wrongly supposed to be new, while the whole set 
belonged in fact to no less than five already established genera. 
