Helminth Fauna of the Dry Tortugas. 171 
One free segment was noticed, which appeared to belong to this species, in 
which there was a slight elongation of the postovarian region, as in P. 
brevispine. 
The uterus is spacious and lies between the ovary and the angle of the 
vagina. ‘The ova are amber color, thin-shelled, mostly collapsed, and con- 
sequently difficult to measure. The cirrus is long, slender, enlarged at the 
base, with exceedingly minute spines, if any. Testes numerous, occupying 
the middle space in front of the vagina. Cirrus pouch behind vagina and 
in its angle, but most of the coils of the vas deferens are in front of the 
vagina. Length in life as much as 60 mm. 
Dimensions of a mounted specimen in millimeters: Length 30; head 
(compressed), length 0.96, breadth 0.96; bothrium, length 0.80, breadth 
0.40; breadth of neck 0.56; distance to first segment, about 1.6; first distinct 
segment, length 0.04, breadth 0.6; mature segments, or maturing segments, 
length 0.80; breadth 0.40; free segments with ripe ova, length 1.8, breadth 
0.6; length of hooks 0.035; ova about 0.025 and 0.018 in the two principal 
diameters. 
This species was found on three occasions in the spiral valve of the 
nurse-shark (Ginglimostoma cirratum). 
July 6, sixteen, in middle of spiral valve and a little below the middle, 
longest about 60 millimeters. 
July 15, two, small. The hooks agree with those collected on the 6th, 
but the worms are much smaller. Length 16 millimeters. 
July 18, three, smallest 30 millimeters in length, longest 35. Hooks very 
small, almost obsolete. 
11. Pedibothrium longispine gen. et sp. nov. 
(Plate 3, figs. 17, 18, 19.) 
Bothria in life elongate, with crenulate borders in fresh specimens, flexi- 
ble, often reflected; at rest and in alcoholic specimens usually longer than 
broad, projecting but little in front of hooks, but in life probably capable 
of being protruded so as to make a small cup. Free margin outside of 
muscular ring narrower than in the other species. Hooks relatively long, 
in some cases equal to half the length of a bothrium. The two hooks on 
each bothrium have their bases apposed and projecting forward to the ante- 
rior end of the bothrium. The two prongs on each hook are long as com- 
pared with the oblong base and are strongly recurved; the outer prong is 
about twice the size of the inner, and both are curved in the same manner, 
so that the two would lie in the same curved surface and be nearly parallel. 
The character of the hooks may be best understood from the figures. The 
neck exhibits various contraction stages in life, but at rest appears to be 
slightly larger than the succeeding part of the strobile. In the mounted 
specimens it was seen to be minutely spinose and distinct from the body, 
