No. 5 meserve: monogenetic trematodes 45 



limbs with lateral branches, unite at posterior end of worm. Testes 

 in median line posterior to ovary, twenty-seven to forty in number, 

 smooth, unlobed, closely packed and irregular in shape. Cirrus 

 spherical with fourteen to sixteen strong double hooks arranged in 

 a circle with powerful sucker just below hooks. Diameter of cirrus 

 0.116 to 0.114 mm. Length of cirrus hooks 0.038 to 0.048 mm. 

 Genital pore well forward in mid-line about posterior part of first 

 eighth of animal, width of opening 0.020 mm. surrounded by cir- 

 cular to elliptical rim 0.036 to 0.040 mm. in diameter. Ovary situated 

 in mid-line in posterior part of first third of animal, ovarian region 

 0.254 to 0.407 mm. in length, diameter of ovary at widest part 0.084 

 to 0.135 mm., U-shaped with open end to right, lower arm smaller 

 in diameter with pronounced enlargement at lower end. Vagina 

 absent. Genitointestinal canal present. Vitelline ducts unite at upper 

 end of ovary to form large yolk duct. Vitellaria extend from genital 

 pore to haptor, separated in front, united behind. Eggs elongated 

 oval with short polar knob at anterior end and long filament at pos- 

 terior end, 0.152 to 0.169 mm. in length by 0.052 to 0.076 mm. in 

 width, length of filament 0.200 to 0.203 mm. 



Comparisons. H. ecuadori is similar to H. tetrodonis (Goto, 

 1894) but is much smaller, 2.9 to 3.4 mm. in length as compared to 

 5.0 to 15.0 mm., has tv/elve to fourteen cirrus hooks as compared 

 to ten and the vitellaria extend to the posterior haptor as compared 

 to vitellaria being absent in posterior half of H. tetrodonis. 



H. ecuadori is named after its geographic location, Ecuador. 



Heterobothrium galapagensis, new species 



(Plate 5, figs. 20-21) 



Host: Paranthias furcifer (Cuv. and Val.) 

 Location: Gills 



Locality: Tagus Cove, Albemarle Island, Galapagos Is- 

 lands 

 Number: 1 



Body thin and flat, anterior end bluntly pointed, 1.560 mm. in 

 length by 0.457 mm. in greatest width at middle of body, left side 

 of body with pronounced outward curve, tapering anteriorly and 

 posteriorly from the middle. Approximately same width across an- 

 terior end in front of haptor. Posterior haptor relatively short and 

 broad, 0.254 mm. in length by 0.542 in width. Four posterior suckers 



