CESTODE AND NEMATODE PARASITES. 73 



TRYGON SEPHEN (FORSK.). 



This fish is known as "Ada tirikkai" in Tamil, and as " Polkolla maduwa" in 

 Sinhalese. A large individual of this species was obtained from the fishermen on 

 Dutch Bay Spit, on January 3, 1905. The breadth of the disc was 47J inches, and 

 the length from the snout to the butt of the tail was 34 inches. 



The stomach itself was empty, but the large intestine was choked with sand, inter- 

 mixed with which were a large number of partially digested skins of worms, 

 apparently Gephyreans. A few limbs of crabs were also present. It would seem 

 that this Trygon feeds principally upon worms, with such small crustaceans as may be 

 associated with them in sand. 



Anthemobothrium, n. gen. 



Fourteen millims. long when preserved. Head about 1 millim. in diameter, almost 

 spherical, with four small suckers in the hinder half, and fourteen feathered bothridia 

 radiating over the anterior half. Neck narrow and short. Proglottides slightly 

 overlapping their successors. The skin is faintly striped. The uterus in the posterior 

 proglottides occupies almost all the space and is crowded with ova. 



Anthemobothrium pulchrum, n. sp. Plate V., figs. 78, 78 a, 786 and 79. 



A single example of this beautiful and remarkable Cestode was found amongst the 

 crowd of Tetrarhynchus leucomelanus and Prosthecobothrium walga taken from the 

 intestine of a Trygon sephen captured in Dutch Bay. 



It measures 14 millims. in length when preserved in formaline, and as the posterior 

 segments are crowded with eggs, it is apparently a full grown worm. The head, 

 which is almost spherical and as broad as it is long, measures just under 1 millim. 

 across (Plate V., fig. 79). The neck is very slender and short, and the body 

 gradually, but slowly, broadens until the last segments are about 0'6 millim. broad 

 by 0'9 millim. or 1 millim. long. 



The head consists of a basal hemisphere bearing four equidistant, small, rounded 

 suckers. From the distal end of this basal part emerge fourteen radiating bothridia, 

 which are flattened down and look like so many neatly arranged ostrich feathers or 

 frilled petals of a flower^ 



The neck is narrow and short. The proglottides soon appear, at first much wider 

 than long, but by the middle of the body they are square, and behind are twice as 

 long as they are broad. The genital pore is not clearly visible, but some proglottides 

 seemed to show an aperture on the flat surface near the anterior end. The uterus 

 arises also at this end and is soon evident as a clear coiled tube. The divisions 

 between neighbouring coils soon break down, and in the last proglottis the uterus, 

 crammed with eggs, occupies almost all the space in the segment. 



Each segment has a very short lip posteriorly, which slightly overlaps the 

 succeeding one. There is also a curious arrangement, probably of glands, in the skin, 



