326 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
ventral and at the distal extremity. Hoek’s figures show a similar 
condition (Iloek, ’ 81 , pi. 14, fig. 5). This protuberance is longer 
and less conical on the third and fourth legs, where it bears the 
opening of the genital duct. I believe that the genital ducts open 
only on these legs, for I was unable to make out a duct in the pro¬ 
tuberance of the first and second legs, or an opening at the apex, 
both of which were plainly evident in the others. Neither do I 
find lateral protuberances on the femoral joint, such as Iloek 
describes and figures, but on the dorsal side of the joint is a long, 
narrow opening with a raised, thin, chitinous edge, and with several 
transverse partitions crossing it (pi. 22, figs. 27, 24). This is 
probably the external opening of the so called ‘femoral gland,’—a 
gland which occurs in the fourth joint of the leg of the males in at 
least a considerable number of species of pycnogonids (Iloek, ’ 81 , 
p. 106). Hoek mentions finding this gland in A. insignis , but says 
it opens by “only a single pore at the end of the joint, placed at the 
tip of a conical excrescence.” 
Comparative dimensions. 
A. insignis. A. insignis bermudensis. 
Length of proboscis, 
2 
mm. 
1.5 mm. 
Total length of body, 
6 
a 
4.8 
n 
Length of abdomen, 
0,5 
n 
0.7 
it 
Length of oviger, 
4.2 
a 
3.4 
u 
Length of leg of 1st pair, 
19 
a 
13 
u 
Extent, 
25 
n 
It will be seen by a glance at the figures above that A. insignis 
bermudensis averages nearly a third smaller than A. insignis 
insignis. 
The most striking character of the Bermuda subspecies is its 
color, which affords a good example of protective coloration. This 
consists of alternate bands of red and yellow on the legs, the yellow 
usually occupying the proximal end of the joint. The trunk is more 
uniformly red. Figure 1 (pi. 20) shows the general appearance 
of the animal in the living condition enlarged four and one half 
times, 1 while figure 2 represents under the same enlargement a 
1 This figure and figure 2 are redrawn from color sketches from the living- 
animals kindly made for me by Mr. H. B. Bigelow. 
