TREMATODE PARASITES. 101 



Acanthocolpus liodorus, n. sp. Plate I., figs. 7 and 8. 



Specific diagnosis. Length 2 millims. to 4 millims., breadth 0*36 millim. to 0*6 

 millim. Diameter of the oral sucker 0'12 millim. to 0*16 millim. Ventral sucker 

 oval, with the largest diameter transverse to the long axis of the body ; length 

 0*18 millim. to 0'24 millim. and breadth 0'24 millim. to 0*3 millim. Distance between 

 the two suckers 0*24 millim. to 0'36 millim. 



Prsepharynx 0'21 millim. to 0'24 millim. long. Pharynx 0'13 millim. to 0*17 millim. 

 long, 0*08 millim. to O'lO millim. broad. Genital atrium 0'4 millim. to 0*7 millim. 

 long, dividing behind the ventral sucker. Vagina about 0*25 millim. to 0'5 millim. 

 long. Cirrus-pouch about 0*5 millim. to 1'05 millims. long, 0*07 millim. to O'lO 

 millim. broad. The long axis of the testes not quite in the long axis of the body, 

 but somewhat oblique, the posterior end directed ventrally and the anterior end 

 directed dorsally, and the two testes overlapping each other a little in this way. 

 Ovary near the ventral surface of the body, partially still ventral from the anterior 

 end of the anterior testes. The testes 0'35 millim. to 0*60 millim. long, 0*20 millim. 

 to 0*24 millim. broad. Diameter of the ovary 0'14 millim. to 0'22 millim. Eggs 

 0'075 millim. long, 0'045 millim. broad. 



From the intestine of Chirocentrus dorab, Cuv. ; from Kalpitiya. About two dozen 

 specimens. 



Schistorchis, n. gen. 



Provisional generic diagnosis. Distomids of large size, with a very muscular, 

 thick and wrinkled body, without spines. Shape almost rectangular, with rounded 

 anterior and posterior ends. Mouth terminal, small, opening into the globular oral 

 sucker. Pharynx well developed ; pr86pharynx as well as oesophagus wanting ; 

 intestinal cceca long. Excretory vesicle Y-shaped, with long median trunk and long 

 paired branches, crossing the intestinal coeca ventrally and finishing near the anterior 

 end of body by the sides of the oral sucker. 



Genital opening just in front of the ventral sucker. Cirrus-pouch well developed. 



Testes in about the middle of the body, divided into several small separated pieces 

 (in the same manner as in Gorgodera), five on the one side, and six on the other, 

 lying for the most part behind each other in two lateral folds, which are separated 

 from each other by the anterior end of the median trunk of the excretory vesicle. 

 As in Gorgodera, the greater number of testes is on the ovarian side. 



Ovary just in front of the testes and between the paired branches of the excretory 

 vesicle, near the median line. Seminal receptacle present. Very numerous follicles 

 of yolk glands on the sides of the body and behind the testes. Uterus very small, 

 corkscrew- like, almost only by the side of the ventral sucker. Eggs clear yellow- 

 tinted. 



Type, and so far the only species of the genus : Schistorchis carneus, n. sp. 



