220 ALICE L. EMBLETON ON A NEW 
discerned (Pl. 22. fig. 11, p), though in this stage it has not yet 
developed its two sete. 
B.—The organ at this stage is larger and more modified, it 
ends in a strong recurved hook (figs. 12, 13); its lower edge is 
fringed with sete, and about a third of the way along this 
border is another spine, almost a strong as the terminal one. 
Laterally, on the inner surface, there is a palp (figs. 12, 18, p), 
the rudiment of which was seen in stage A, but now it bears two 
long terminal sete; this palp is apparently a moveable organ 
and serves as a brush. 
C.—This is a very interesting stage, for one can make out 
within the chitin of the maxillipede two folded hooks; the 
terminal spine and sete of stage B remain, but the palp is not 
always present at this stage. It is obvious that the two immature 
enclosed hooks belong to the new appendage, and that they will 
unfold at the next moult when the old chitinous coat is shed 
(fig. 14). 
D.—This is the largest and final stage in the development of 
this appendage. All sign of setose fringing is gone along with 
the palp (fig. 15). It is now a clearly-outlined claw-like organ, 
ending in a powerful recurved tip, directed backwards; along the 
posterior surface is a second, stout, hooked process. It is probable 
that this organ is prehensile, and helps to fix the parasite securely 
to its host. 
First Maxillipede 3 —I find this limb is unaltered in all the 
stages in the male, except that in its very early stages it has 
sete on its surface as well as on its edge. It is a flattened 
petaloid plate of chitin, having its free border fringed with fine 
sete (Pl. 22. fig. 16); and is evidently greatly reduced, for it 
resembles the first and very undifferentiated form which this 
appendage has in the stage A of the female. The’ first is applied 
closely to the highly-specialized second maxillipede, from which, 
however, it can be detached by careful dissection of a specimen 
boiled in potash. Judging from the three known genera, I had 
expected to find this appendage highly developed in the male, as 
it isin all the three allied forms, where, however, it is alike in the 
two sexes, being a short solid organ with two joints and armed. 
with hooks and sete. That it should be so degenerate in 
Goidelia in the male is a very remarkable fact, and serves to 
distinguish this from any other form. 
Second Mawillipede 2 .—This is very feebly developed in all 
