36 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



small, smooth, elliptical bodies, broader than long, 0.056 to 0.067 

 mm. in length by 0.101 to 0.118 mm. in width. Similar structures 

 were first described by Goto (1894) in Benedenia ovata. Their func- 

 tion is problematic. The name glands of Goto is proposed for them. 

 The cirrus sac extends less than halfway between oral sucker and 

 ovary. Prostate glands fan-shaped, opposite cirrus sac, extending 

 nearly to lateral edges of body and posteriorly almost to the ovary. 

 The genital pore to the left opposite the middle of the oral sucker. 

 Ovary median, partly pretesticular, partly between the anterior edges 

 of the testes, elliptical, 0.305 to 0.557 mm. in length by 0.237 to 

 0.339 mm. in width, and pierced by eleven dorso-ventral muscles. 

 Seminal receptacle intraovarian. Vitellaria extending from the oral 

 sucker to the posterior end of the body. Yolk reservoir just anterior 

 to ovary, transversely extended, constricted in middle. Vagina not 

 seen. Egg triangular in surface view, 0.101 by 0.130 mm. with short, 

 curved, stout appendage at one pole and a long, slender filament 

 at the other. 



Comparisons. B. isabellae differs from B. ishikawae in possessing 

 lobed testes and glands of Goto; from B. ovata in possessing lobed 

 testes and nonindented haptor; from B. epinepheli in possessing 

 lobed testes, perforated testes, more posterior genital pore as well 

 as different hooks. It is most similar to B. melleni but has larger, 

 more elongated, more lobed testes with more numerous perforations, 

 with more expanded prostate glands, and glands of Goto. 



This species is named after its geographic location, Isabel Island, 

 Mexico. 



Benedenia adenea, new species 

 (Plate 4, figs. 3-4) 



Host: Mycteroperca sp. 



Location: Gills 



Locality: Socorro Island, Mexico 



Number: 5 

 Body elongated oval, 1.7 to 2.9 mm. in length by 1.256 to 1.773 

 mm. in greatest width. Posterior haptor circular, with indentations 

 which form five lobes, 0.678 to 0.953 mm. in diameter, with irregu- 

 larly notched, relatively wide marginal membrane. The anterior pair 

 of hooks 0.084 to 0.118 mm., strong with relatively long projecting 

 piece slightly oblique and posterior to base of hook, straight with 

 points anterior in floor of haptor. Middle pair of hooks 0.169 to 



