142 
DB. E. YON WILLEMOES-STTHM ON THE 
much the labrum of the southern larva, in which, however, there are five large spines 
and three small ones on each side. 
At the top of the labrum is the round opening for the mouth, leading into an oeso- 
phagus which runs through the middle of the labrum. At the point of attachment this 
oesophagus is covered by a large pigment-spot (fig. 15, pi), on both sides of which two 
glands are seen, which first seemed to me to run into the stomach (fig. 15, coe ) ; but 
afterwards I could never find any communication between the two, and I am very much 
inclined to see in these two glands those which in the Cypris are to be seen close to 
the stomach, and which send their ducts up into the antennae. Dohrn has seen these 
glands, hut has not been able to identify them as such, as his specimens were rather 
badly preserved. 
The oesophagus leads into a stomach, or stomachial intestine ; for the stomach is not 
so strictly separated from the intestine as might appear from fig. 15, which, however, 
is quite correct, in so far as in animals which are alive there is a strong constriction to 
be seen. Especially the upper portion is covered with a strongly pigmented epithelium, 
which in our drawing (fig. 15) has come out a little diagrammatically, as in reality 
the hexagons are not so regular as they appear there. I found the upper portion of 
this intestine filled with small algae allied to coccoliths &c. In the lower portion the 
pigment of the cells is less intense, which makes it appear more even, less dark, and of 
a light brown colour. The intestinum rectum is, as a rule, filled with granulated 
excrements, and leads to the anus, which may be easily discovered by getting a side 
view of the tail between it and the caudal spine (fig. 15, as). On both sides of the 
rectum there is a glandular coating, and another larger gland, which is enclosed in the 
tail (fig. 15, gl), is seen to go into the lower portion of the intestine. 
Both the tail and the large caudal spine get their muscles from the upper centre of 
the carapace, where they are attached near those of the dorsal spine. 
The caudal spine is covered, like the dorsal, with recurved spines. In old Nauplii this 
spine is more than double the length of the tail. Between the two there is a bunch of 
red feathery hairs, just in the same place where three such hairs have been described 
by Dohrn (see his pi. 29. fig. 6). Here there are four of them, one of which is very 
much longer than the others. 
In the tail (Plate 12. fig. 15, and Plate 14. fig. 22) we find (1) six pairs of movable 
spines, each of which has muscles running to it; (2) somewhat lower down a pah’ of 
spines which are not movable, but recurved ; (3) a pair of large, nearly straight spines, 
and between these last two (4) patches of exceedingly minute and forked spines (Plate 14. 
fig. 22, ay). The remaining part of the tail is covered with the ordinary sort of spines 
which have just been mentioned in the large caudal and dorsal spines. 
After the third of the movable spines has come out ( i . e. after the fourth moult), 
one may find, in those specimens which are ready to moult again, seven segments 
under the skin, each of them with an appendage which looks very much like a future 
swimmerette (Plate 13. fig. 19, sp 2 ). The same thing may also be found in those sped- 
