XIII. ON MESOCOELIUM SOCIALE (Liihe). 



By R. B. Seymour Sewell, B.A., F.A.S.B , I. M.S., 



Offg. Superintendent, Zoological Survey of India. 



This species of Trematode appears to be widely distributed 

 throughout the tropical and sub-tropical zones : it was first dis- 

 covered and described by Liihe (1901, p. 171) from Bufo mela- 

 nostichis Schneid. from the East Indies ; subsequently Odhner (igi r, 

 p. 88, footnote) obtained specimens, also from Bufo melanostidus , 

 in material sent to the Berlin Museum from the island of Biliton in 

 the Dutch East Indies between vSumatra and Borneo, and the same 

 author also records its occurrence in a species of Bufo obtained 

 by Fiebrig in Paraguay. 



This Trematode was first found by me in a specimen of Bufo 

 melanosticius, caught in the compound of the Indian Museum, 

 Calcutta, in May, 1919 ; subsequent examination of other specimens 

 of this toad obtained from the same locality proved that at this 

 period of the year infection with the parasite is heavy and wide 

 spread and in Table I I give a record of m^^ observations during 

 the months of May and June, rgig. 



Table I. 



Record of occurrence of Mesocoelium sociale (lyiihe) in Bufo 

 melanostictus. 



