RESEARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 21 3 



most numerous at its upper part. The females are viviparous and 

 contain living young. 



In one Terrapin only, also in the intestine, there were two flukes, 

 the Auiphistomuvi graiidc, about half an inch long. 



In the bladder of another Terrapin there was a single Polxstomum 

 3.5 mm. long, probably/', oblongwn, first described by Prof. Wright, 

 of Toronto, from an individual obtained from the bladder of the 

 Musk Turtle, Aromochelys odoratns. 



In another Terrapin he had found four Polystomes, of which 

 three were in the throat and the other in the nose. These pertain 

 to a different species from the former, and may prove to be the Poly- 

 stonniiii occUatuin, found in a similar position in the European Turtle, 

 Emys enropa'a. At the genital outlet of Polystovuou , situated ven- 

 trally at the fore part of the body, the cirrus is surrounded by a 

 circle of hooks. In P. iniegcrrim^uii, the species best known and 

 found in Europe, living in the bladder of frogs, the genital circle is 

 composed of eight hooks. Prof. Wright ascribes sixteen hooks to 

 the circle of P. oblotigiivi, and this accords with the number in the 

 Polystomum from the bladder of the Terrapin. In the other Poly- 

 stomes of the latter he found the circle to be composed of thirty-two 

 hooks. Siebold sa3'S there are forty hooks to the circle in P. occlla- 

 tum. Dr. Zeller figures the latter from a sketch of vSiebold, in 

 which the caudal disk is represented as having two large hooks and 

 eight small ones between the posterior pair of bothria. In the allied 

 Polystomes of the Terrapin the number and arrangement of the 

 hooks of the caudal disk is the same as represented in Prof. Wright's 

 figure of P. oblongum. If, then, we have a correct record of the 

 facts, the Polystomes of the fauces of our Terrapin may be regarded 

 as another species, which ma}' be distinguished as follows : 



Polystomum coroiiatum. — Body when elongated lanceolate. Caudal 

 disk wider than the body, cordiform, with three pairs of bothria and 

 with the body attached between the anterior two pairs ; changeable 

 in form to oblong, circular or quadrate ; with three pairs of minute 

 hooks between the anterior pair of the bothria and with a larger 

 pair and two small pairs between the last pair of bothria. Genital 

 aperture with a circular or a transverse oval coronet of thirty-two 

 hooks of equal length. No eyes visible. Length elongated from 

 4 to 6 mm. ; contracting to about half the length and widening 

 proportionately. 



Besides the foregoing, there was found in the intestine of one of 

 the Terrapins a little Distome, of 3 mm. length, which, though ma- 

 ture, he had not the leisure to examine. He also observed in the 



