534 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 57. 



contracted individuals 0.75 to 0.8 mm., breadth 0.4 to 0.5 mm. Cutic- 

 ular scales relatively narrow, close together. Ventral sucker always 

 twice or more than twice (two to two and one-fourth times) the size 

 of the oral sucker. Genital sucker about two-thirds the diameter of 

 the ventral sucker. Average diameter of oral sucker, 62 [jl; of ven- 

 tral sucker, 150 (x ; of genital sucker, 104 \i.. Chitinous rodlets of geni- 

 tal sucker, TO to 80 in number. Vitellaria, consisting of about 14 

 lobules in each lateral field, extend forward to about the level of the 

 anterior border of the ovary. Eggs bright yellow in color, about 30 

 by 17 [X. 



Host. — Milvus aegyptius {=31. parasiticus). 



Location. — Small intestine. 



Locality collected. — Egypt. 



This species formerly included in H. heterophyes was separated 

 from it by Looss (19027i) on account of certain differences in the rela- 

 tive dimensions of the suckers, and the color of the eggs. 



HETEROPHYES FRATERNUS (Looss, 1894) Looss, 1902. 



Fig. 3. 



1894. Distomum fraternum Looss, 1894^?, pp. 42-48, pi. 2, iig.s. 13-15 (in 



Pelecanus onocrotalus; Egypt). 

 1899. Coenogonimus fraternus (Looss, 1894) Looss 1899&, pp. 585, 700-701. 



1901. Cotylogonimus fraternus (Looss, 1894) Bbaun, 1901 e, p. 337. 



1902. Heterophyes fraternus (Looss, 1894) Looss 1902/», pp. 785, 808, 



809, 838, 854. 



Specific diagnosis. — Heterophyes: Largest most extended indi- 

 viduals nearly 0.6 mm. long, usually 0.4 to 0.5 mm. and about 0.3 

 mm. wide. Cuticular scales relatively long and narrow, very close 

 together. Ventral sucker and genital sucker almost equal in size in 

 young individuals, and somewhat larger than the oral sucker, in 

 older individuals the ventral sucker being larger than the genital 

 sucker. Average diameter of oral sucker, 50 [x; of ventral sucker, 

 70 [i ; of genital sucker, 60 [i. Chitinous rodlets of the genital sucker 

 65 to 75 in number, the circlet presenting the appearance of a fine 

 comb or brush in certain stages of contraction of the sucker. In- 

 testinal ceca always extend behind the testes and terminate near 

 the wall of the excretory vesicle. Vitellaria consisting of 10 to 12 

 lobules in each lateral field extending forward only as far as the 

 level of the posterior border of the ovary. Eggs about 20 by 10 [l 

 in diameter, shell about 1 [jl thick; color never darker than a light 

 yellowish-brown. 



Host. — Pelecanus onocrotalus. 



Location. — Small intestine. 



Locality collected. — Egypt. 



