JOURNAL OP THE COLLEGE OF SCIENCE. TOKYO IMPERIAL UNIVERSITY. 



VOL. XXXIX., ART. 8. 



On Dissotrema papillatum, n. g., n. Sp., an Amphistomoid 

 Parasite from a Marine Fish. 



By 



Seitaro GOTO, 



Professor of Zoology in the Science College, Imp. Univ., Tokyo, 



and 

 the Late Mr. Yasunaga MATSUDAIRA, Rigakushi* 



With one Plate and two Text-ßgures. 



This trematode occurs in the rectum of Sigamts fuscescens 

 (Houttuyn), a marine fish distributed from Tokyo southwards to 

 the Philippines. Of about fifteen fishes examined by us more 

 than half were found to contain the parasites, varying in number 

 from a few to fifty or seventy in a single fish. The form of the 

 body is strikingly like that of a Paramphistomum, so that we at 

 first thought that the parasite belonged to that genus; but a cur- 

 sory examination of the internal organization convinced the senior 

 author at once that it could not possibly be referred to the same 

 genus, and so a detailed study of it was undertaken. 



The body may be 3.5 mm. long by about 0.6 mm. at the 

 broadest part; in mounted specimens flattened under the pressure 

 of a cover slip it may be as wide as 1 mm. It is sausage shaped, 



* Mr. Yasonaga Matsudatra was born in Tokyo on the 28th of May, 1889, as the eldest 

 son of Viscount Yasutami Matsudatra, formerly Prince of Tsuyarna in the Province of Mi- 

 masaka. After completing the necessary preliminary education, he entered the Science Sec- 

 tion of the First High School and was admitted into the Science College of this University in 

 July, 1910. He finished the course in Zoology with credit in July, 1914, presenting as his 

 graduating thesis a paper on the trematode described here. Shortly afterwards he was taken 

 ill and died on the 19th of October, 1914. He leaves behind him the memory of an earnest 

 and loyal character and his early loss is deeply mourned by all who knew him. 



I have examined Mr. Mat-udaira's slides and added some observations and drawings of 

 my own. The text has been rewritten. S. Gr. 



