152 DR. W. NICOLL ON TREMATODE 
the ventral sucker, but in the older specimens it overlaps the 
posterior border of the sucker. It is not much raised above 
the surface of the body, and is traversed by a deep median 
longitudinal furrow which extends along its whole length. In 
well-expanded specimens the furrow is much shallower. A 
similar furrow exists in H. pileatwm (Rud.). 
The genital glands do not display any striking peculiarities, 
except that the testes are reniform in transverse section and the 
yolk-glands extend forward only to about ‘5 mm, from the 
anterior end. Their auterior edge forms a semi-circle with the 
convexity directed forward. 
The ova measure “105—1] x -065- 07 mm. 
This species bears most resemblance to H. spathula (Creplin), 
but differs from it in several important details. In the latter 
the two parts of the body are nearly equal; the oral sucker and 
the pharynx are only half as large, while the clinging-plug is 
much larger and does not display the longitudinal furrow. The 
yolk-glands, too, are probably more extensive. 
The following is a list of the hosts and of the Trematode 
parasites obtained from them :— 
MAMMALS. 
ANOA DEPRESSICORNIS. 
Fasciola gigantea (Cobbold) ..................... Laver. 
BIRDS. 
CIRCUS HRUGINOSUS. Marsh Harrier. 
Metorchis crassiusculus (Rud.)................... Liver and Gall-bladder. 
BuBo ASCALAPHUS. Kgyptian Eagle-Owl. 
Hemistomum canaliculatum Nicoll ............ Intestine. 
LaRuUS RIDIBUNDUS. Black-headed Gull. 
Gigantobilharzia acotylea Odhner ............ Mesenteric veins. 
LARUS FUSCUS. Black-backed Gull. 
Tocotrema lingua (Creplin) ..... ........-.....- Intestine. 
LARUS ATRICILLA. Laughing Gull. 
Tocutrema lingua (Creplin) ...... .............. Intestine. 
ALCA TORDA. Razorbill. 
Hemistomum pileatum (Rud.) ................-. Intestine. 
Metorchis xanthosomus (Creplin) ............... Gall-bladder. 
(EDEMIA NIGRA. Black Scoter. 
Catatropis verrucosa (Froelich)  ............... Ceea. 
Paramonostomum alveatum (Mehlis) ......... Intestine. 
Lorivs DOMICELLA. Purple-capped Lory. 
Lyperosomum seitulum Nicoll ............... Liver. 
PHENICOPTERUS RUBER. Ruddy Flamingo 
Echinostomum aliud Nicoll ..................... Intestine. 
CRAX ALECTOR. Crested Curassow. 
Lyperosomum direptwm Nicoll ............0:-. Liver, 
