DEVELOPMENT OE CIRRIPEDIA. 
151 
turns like a corkscrew. In the tail there is a gland (gl) which seems to have 
its opening into the lower part of the stomach. The epithelium in the upper 
part of the stomach is a little diagrammatic, not being in reality quite so 
regular, and the cells being more darkened by granules than they are in the 
figure. 
Letters the same as in the last figures, except : — sp 2 , immovable large spine ; pi, pig- 
ment-spot, just above the entrance of the stomach; as, anus; r, processus 
mandibularis. Natural size : — 
. 1-0 millim. 
. 4-0 millims. 
Diameter of carapace 
Length of tail . . . 
Fig. 16. One of the processes on the carapace of the Archizoea (later Nauplius stage), 
showing the glands terminating in them and the nerves in connexion with 
these glands. Observed on a living specimen under very high power 
(Hartnack no. 10). gl, the large and main gland opening into pr, the pro- 
cess of the carapace ; m, outer margin of the carapace ; y , a sense-hair on 
the same ; n, varicose nerve running up to it ; n, nervous stem sending a 
branch to the bottom of the gland, gl ; c , a ganglionic cell. 
Fig. 17. One of the lateral horns seen from above. H. y. From a living specimen. 
gl, the large glands, the bottoms of which are fastened by fibres of (?) con- 
nective-tissue or muscles ; pr, processes in connexion with smaller glands ; 
q, ring for the attachment of the muscles ; cli, inverted portion of chitinous 
cuticula ; y, a sense-hair ; z, hairs at the top of the lateral horn, very likely 
in communication with a nerve, which, however, could not be found. 
Fig. 18. Eye of a young Nauplius after its fifth moult, and on both sides the feelers 
with their nerves. Underneath the two ganglia. Very high power. H. 
x, feeler ; n, varicose nerve ; cer, ganglia ; between the eye and the feelers 
a granular (? nervous) substance. 
Fig. 19. Portion of the tail of a Nauplius after its fourth moult. Only three large 
flexible spines have as yet come out (sp), but seven spines ( sp 2 ) may be seen 
ready to come out under the skin. The seventh is the future large immovable 
spine. High power. 
Fig. 20. The tail of an adult Nauplius (last Archizoea stage) showing the muscles 
going to the movable spines. High power. 
Fig. 21. The ganglia (cer) of the Cypris stage ; the nerve going to one of the compound 
eyes (oc), and the capsule round the latter. High power. The connecting 
dotted line (Ay) between the two ganglia indicates that it is a hypothetical 
one, not observed. 
