Amphipod Orchestia tucurauna, Fritz Miller. 377 
-resemblance of the second gnathopod to that of my Picton 
specimens, A comparison of my specimens with Stebbing’s 
description and figures of O. sulensont made it appear very 
probable that they belonged to the same species, though the 
palm of the second gnathopod of O. sulensoni is shown con- 
siderably more oblique and that species was supposed to have 
been obtained at Madeira, the locality, however, being 
doubtful. 
Stebbing states that his species agrees with the imperfectly 
described O. tucurauna, Fritz Miiller, in regard to the finger 
and the notched palm of the second gnathopods, but appears 
to differ in not having the fourth and fifth joints of the fifth 
pereopod thickened or broadened. In turning up Fritz 
Miiller’s reference to his specimen in ‘ Facts and Arguments 
for Darwin, 1869, p. 79, I find that the second gnathopod 
of the male, as figured by Fritz Miiller, agrees pretty closely 
with that of the Picton specimens, and that, moreover, the 
description given by Fritz Miiller of the changes that take 
place in the males even after they attain sexual maturity and 
his account of the more immature males agree very well 
- indeed with those exhibited by the Picton specimens. Thus 
I had already noted that in them the first few joints of the 
flagellum of the second antenna were more or less completely 
fused in the fully developed males and that in the young 
males the process on the finger and the corresponding notch 
on the palm of the second gnathopod were only slightly 
developed. ‘There seems little doubt that the specimen 
described by Stebbing as O. sulensoni is really the same as 
Miiller’s O. tucurauna. Stebbing’s description of the various 
characters not mentioned by Fritz Miiller agrees closely with 
the Picton specimens ; thus, while the basal joint 1s oval in 
the third and fourth pereeopods and partially so in the fifth, 
its hind margin in that limb is almost quite straight as 
described by Stebbing. In my specimens, in the better 
developed males the second antenne are strong and have the 
last two joints of the peduncle considerably broadened, but in 
none of my specimens have I seen the fourth and fifth joints 
of the fifth pereeopod specially broadened; they are compara- 
tively slender, as drawn and described by Stebbing. I have 
little doubt, however, that Fritz Miiller is right in saying 
that this character is shown only in the older males and is 
not fully developed until after they come to sexual maturity, 
I have often noticed the same thing in the nearly allied 
species OQ. chiliensis, M.-Hdw., where the males may have the 
characteristic form of the second gnathopod and of the an- 
tenn, though they have not yet developed the thickened 
