A SMALL COLLECTION OF AMPHIPODA FROM JUAN FERNANDEZ. 85 
ever, may be due to the selection of larger specimens by the collector, though 
when collecting this species on the coast of New Zealand I have usually found 
the males fairly numerous. The other specimens which have the second 
gnathopod small and not subchelate are considered to be either females or 
immature males, all of these are smaller than the males. 
The specimens in tube No. 729 marked »Masatierra, under stones» are | 
think young forms of the species now under consideration. The same is true 
of those in tube No. 494, labelled »Masatierra, among withered leaves.» None 
of the specimens in these two tubes shows the adult characters of the male or 
bears eggs. 
The specimens in the two tubes, No. 327, 
are of special interest as they were obtained 
500 metres above sea level. In one tube are 
about a dozen large specimens, averaging about 
12 mm. in length. One of these is a male, 
fully developed, showing the usual male char- 
acters as mentioned above and having the 
expansion of the joints of the fifth peraeopod 
slightly greater than in any of the specimens 
in tube 259 which, presumably, were obtained 
from about the sea level. The other specimens 
in tube 327 are apparently females or young 
males. One of them which I dissected was a 
female with about 7 or 8 eggs in the brood 
pouch. Most of these eggs were very hard, 
almost stony, but whether this was the result 
of the action of the preservative or from path- 
ological cause, I cannot say. In the other 
tube, also marked »No. 327, under stones, 500 
metres above sea level,» were small specimens 
about 4 mm. in length which are doubtless 

young of this same species. Fig. 1. G, Orchestia chiliensis, Head 
; , and antennae of male with abnormal 
Of the specimens found »in a brook» number of joints in the second 
No. 724, two appear to be immature males Aaa 
showing male characters in the gnathopods, 
and the rest apparently females. These two males illustrate to some extent 
the stages passed through in the development of the adult male characters. 
The larger one about 6 mm. long, has the first gnathopod (fig. 1, C) well devel- 
oped, the carpus and propod being produced posteriorly into the characteristic 
pellucid lobes but not to the same extent as in more adult males, while there 
is no sign of a similar lobe on the merus; the second gnathopod (fig. 1, D) 
has the propod large, widening a little distally, the palm nearly transverse and 
regularly even with a small groove as usual for the reception of the tip of the 
finger. In the other much smaller specimen, the first gnathopod (fig. 1, E) is 
stouter than in the females, but none of the pellucid lobes are developed, the 
palm being straight or slightly concave and not extending beyond the tip of 
the finger; the second gnathopod (fig. 1, F) is rather stouter than in the female 
