BARBADOS-ANTIGUA REPORTS 27 
segment while in the male it is but little more than one-half 
as broad. In the male there is also a small slender apical style 
on each side of the subgenital plate near the circus; in the female 
there are no such styles. There are other external differences 
and the concealed genital structure differ greatly. 
In the genital chamber of the male there are a number of 
chitinized or partly chitinized structures, the most conspicuous 
of which are the following: On the right hand side of the cham- 
ber, and situated high up near the supraanal plate is a yellow 
subchitinized organ shaped as in fig. 2, the pointed end directed 
GE 
Figure 2 
to the left and upwards, the basal portion roughly subtriangular 
in section and the curved horn-like extremity subcylindrical ; 
anterior of the above noted organ and slightly nearer the median 
line, and so far back as to arise almost beneath the preceeding 
ventral segment of the abdomen and easily escaping notice if 
but casually examined, is a piceous, fully chitinized, upwardly 
and outwardly curved object, laterally somewhat flattened, the 
apex bifureate, each branch flattened and apically rounded, the 
lower one about one-half as long as the upper one. In the center 
of the chamber is an unchitinized rounded flap apically bearing 
several stout, acutely triangular and laterally flattened teeth, 
and above it, lying between it and the dorsal wall, is a black 
chitinized organ consisting of a sort of obtuse V-shaped piece, 
the closed end directed caudad, the left arm very broad and so 
closely attached to the fleshy flap beneath it as to appear but a 
narrow strip unless elevated especially for examination; the 
right arm is apically free, forming a rounded, slightly recurved 
club-shaped appendage. In the left side of the chamber, and 
well back, is an apically rounded, slightly chitinized flap, the 
basal portions, so deeply embedded in tissue as to be difficultly 
seen, showing some more fully chitinized margins and may ter- 
minate further back in a long spine, or other appendage, though 
no such is to be seen in moderate dissections. The thickened 
and chitinized upper margins of the chamber and the inner 
