Parasites from the Zoological Gardens. 



349 



3 



doubt, however, of the identity of our fluke with, his Fasciola 

 coliibri. This trematode is much elongated in form, flat, covered 

 with little spines, and about one-third of an inch 

 in length, on the average. It is furnished with 

 a well-marked oesophageal bulb, two simple diges- 

 tive tubes, and largely developed reproductive 

 organs. Our specimens were obtained on the 

 20th of February, 1857. 



4. Distoma coronarium. — This species is rather 

 a prettily marked one, owing to the presence of a 

 well-defined coronet of twenty-four spines which 

 encircle the so-called head and mouth. On the 

 25th of December, 1 860, we took large numbers 

 from the alimentary canal of an alligator. The 

 general aspect and character of this species is 

 admirably represented in the accompanying wood- 

 cut, which is copied from an original drawing made 

 with the aid of a camera. This species has an 

 average length of about one-fourth of an inch, but 

 it is only about l-30th of an inch in breadth. 

 The body is linear, flattened, subcorneal in front, 

 and somewhat attenuated posteriorly. The ventral 

 sucker is less than one-half of the size of the oral 

 opening, including the muscular cup. The body _. 

 generally is smooth; the spines of the mouth being 

 conical, pointed, and circumferentially disposed at the margin 

 of the prominent lip. They form pretty micro- 

 scopic preparations when preserved in glycerine. 



5. Distoma conjunctum. — On the 24th of De- 

 cember, 1858, a considerable number of small 

 flukes were obtained from the liver of an American 

 fox, and as the species in question forms an ad- 

 mirable type of the genus Distoma, we have not 

 hesitated to give an enlarged representation of it 

 in the accompanying plate. In group (Fig. 1) 

 eight individuals are represented of the natural 

 size, and the accidental circumstance of finding 

 two of them united by their suckers suggested 

 the specific name above indicated. We have sel- 

 dom seen a Distome in which the visceral arrange- 

 ments were so simple, distinct, and compact as in 

 this ; and therefore to facilitate the investigations 

 of those who are desirous of commencing a study 

 of the organization of these curious parasites, we 

 invite attention to the character and disposition of its internal 

 organs. In Fig. 2 we have a view of the ventral surface of 

 one of the individuals magnified thirty-five diameters linear. 



Distoma 

 coronarium. 



