1903.] ON THE ENTO- PARASITES OP THE " SKEAT EXPEDITION." 145 



5. On the Euto-Parasites collected by the " Skeat Expedition^' 

 to Lower Siam and the Malay Peninsula in the Years 

 1899-1900. By Arthuk E. Shipley, M.A., F.Z.S., 

 Fellow and Tutor of Christ's College, Cambridge, and 

 University Lecturer in the Advanced Morphology of the 

 Invertebrata. 



[Received May 28, 1903.] 

 (Plate XYI.*) 



C est parmi les parasites etnon cliez I'homme quHlfaut^chercher le dernier mot 

 de la creation. , Elie Metchnikoff, 



' Etudes sur la Nature Humaiue.' 



The collection made by the members of the Skeat Expedition 

 of Entozoa was rich and varied, and inasmuch as it was gathered 

 in a land hitherto unsearched for this purpose, it is not surpiising 

 that it contained a large proportion of new forms. Amongst the 

 more interesting of the results brought to light by the investiga- 

 tion of the material are : — (i.) A new species of Tetrarhynchus 

 found in a Holothurian. This is, I believe, the first record of a 

 Tetrarhynclms being found in any Echinoderm, and indeed the 

 presence of Tetrarhynchidse in invertebrates at all is only recorded 

 for one or two Molluscs and doubtfully for a species of Aphrodite. 

 (ii.) An undeterminable species of Tetrarhynchus from a sea-snake. 

 Here, again, we have an entirely new host, no Tetrarhynchus 

 having been hitherto found in any vertebrate outside the class 

 Pisces with the exception of the Ghelonian Testudo mydas. 

 (iii.) A considerable collection of new forms of Acanthocephala. 

 The Nematodes, which have been described elsewhere by Dr. von 

 Linstow, inckide some fourteen new species. 



As will be seen, the collection covers a wide field and includes 

 representatives of the Sporozoa and all the chief groups of metazoan 

 Entozoa, except the Trematoda. The Cestoda, Acanthocephala, 

 Nematomorpha, Nematoda, and Linguatulida severally contribute 

 one or more species to the total. 



With regard to the localities, the parasites were collected mainly 

 in three or four places : Biserat, in Jalor, a province of Lower Siam, 

 in Kwala Aring in the same province, and at Tremangan. 



CESTODA. 



Fam. BoTHRIOCEPHALIDiE. 

 BOTHRIOCEPHALLD LARVyH. 



The snakes of Lower Siam seem frequently to harbour the large 

 larval form of certain of the Bothriocephalidfe, of which it is 



* For explanation of the Plate, see p. 156. 



Proc. Zool. Soc— 1903, Vol. II. No. X. 10 



