ENTOZOA 429 



II. PLATYHELMINTHES. 



A. Trematoda. 



(i) Distoma clavatum Rud. 



Found in the stomach of the Coryphaena hippuris. Several other unidentified 

 species of Trematode were met with in other fish. 



(2) Distoma hepaticuin^ L. 



The presence of this parasite caused a veritable epizootic amongst the cattle on 

 many of the islands of the Hawaiian Archipelago. Horses, though to a less extent, 

 and wild swine are also said to have suffered. Dr Lutz was successful in cultivating 

 the embryos of the Fluke, and he also succeeded in finding and observing the develop- 

 ment of the Redia in the fresh-water snail Limnaeus pei^eger. In his second paper' 

 Dr Lutz gives the opinions of certain distinguished conchologists on the species of water 

 snails which he found infected with the larvae of Distoma. These Molluscs seem to 

 afford matter for a considerable amount of disagreement and the reader is referred to 

 this paper for the details of the subject. Dr Alvarez, to whose kindness I am indebted 

 for several details in this paper, tells me that this Fluke sometimes attacks man. 



B. Cestoda. 

 (i) Drepanidotaenia kemigtiatki- Shipley. 

 Plate XIII. 



The specimens of this tapeworm, of which I received but ten, are all small ; they 

 vary in length from 10 mm. to 22 mm. The head is very small ; immediately behind 

 it, there being practically no neck, the body begins to broaden out, and in some 

 specimens the proglottides attain a width of 2 mm. The segmentation of the body 

 commences immediately behind the head, and is very well marked a little further back. 

 The posterior border of each segment overlaps the succeeding one with a prominent 

 edge or rim ; this is well shown in longitudinal section (fig. 6). The number of 

 segments varies from some fifty to si.xty to over a hundred. The measurements given 

 above are about the average, but, as is well known, tapeworms are extremely extensible 

 animals, and this to a great extent diminishes the value of figures quoted in reference to 

 their size. In some of my specimens the body is stretched, and the length of the seg- 

 ments equals one-half or even two-thirds of their breadth, but in the commoner forms 

 the segments are very short and broad, sometimes eight or ten times as broad as long. 

 They are flattened, as is seen in transverse section, and sometimes, especially towards 



' Centrbl. Bakter. ix. 1892, p. 783, and xni. 1S93, p. 320. 



' The description of this species is reprinted (witli certain alterations) from the Quart. J. Micr. Sci. XL. 

 1898, p. 613. 



