138 
EE. E. YON WILLEMOES-SUHM ON THE 
same species together with those Nauplii when we were south of Australia ; but I had 
unfortunately not examined at that time the first stages of Lepas australis, which 
would doubtless have led me to the young “ Archizoea.” However I have a good 
chance as we go through the straits of Magellan to get them again, and hope that I 
shall have the embryos of Lepas australis in our globes. 
I shall now proceed with the description of our larvae. 
After the second moulting (or the third if one counts the throwing-off of the thin 
cuticle) two great changes occur which totally alter the look of the Nauplii. In the 
first place we find on the hack (which was hitherto somewhat conical, but had no pro- 
tuberance) a large spine (Plate 11. fig. 14, ad), which has already very nearly the length 
of the caudal one, with which it is now growing in equal proportion. In the second 
place the carapace, which formerly exhibited only two small spines (figs. 13 & 14, z ), 
shows now six acute processes, two of which are situated in the front line between the 
two horns, and two others, a smaller and a larger one, on each side. These processes 
are not spines, in so far as they are not closed at the top ; they have an opening there, 
and the chitinous substance is pushed in a little into them up to the point where it 
meets the duct of the glands, which are to be seen at the base of all these processes. 
These glands are as yet unicellular, the same as they were in the last stage. Bourn 
says, in describing his Nauplius, that he suspects the ramified glands to have been 
preceded by unicellular ones — a supposition which is borne out by the facts. The 
appendages show as yet no change, nor do the tail and its spine, in which there are as 
yet only two of the large secondary movable spines (Plate 11. fig. 14). 
On both sides of the eye, between the two tentacles or feelers, there is a granulated 
substance, which I thought at first was the brain ; but afterwards I found the ganglia 
underneath it (fig. 14, cer), and have never been able to make out what this granulated 
band represents. 
The upper lip now not only includes the oesophagus, but also two glands or caeca 
(fig. 14, coe ), in the place of which we saw in the last two stages an assemblage of 
slightly granular cells. There are now two strong spines on both sides of the edge of 
the labrum, which has very much the form which it retains during the whole Nauplius 
stage. 
Also the top of the lateral horns (fig. 14, cp) has changed. We find two pointed 
chitinous prolongations, and between them a great many fine setae occupying the 
edge of the rounded margin. The dimensions of the embryo in this stage are as 
follows:— millim. 
Width of carapace 025 
Length of cornua parietalia 021 
Length of carapace 0”32 
Length of tail 0‘66 
Total length 0*98 
Width of frontal line 0T1 
