FASOIOLA. 33 



CHAPTER III. 



PARTICULAR TYPES. 



Structure of particular trematode types — Fasciola — Grasterostoma — Campula — Bilharzia 

 — Ecliiiiostoma — Family of the Tristomes— Tlieir development and Genera — The 

 Polystomes — Genera — -The Gyrodactyles — Wedl's researches respecting their orga- 

 nization — Development — Von Siebold's and Van Beneden's opinions contrasted. 



IJndee this head I first proceed to offer a few remarks respect- 

 ing one or two of the more striking or otherwise interesting 

 forms belonging to the last- described family of Trematodes, 

 These descriptions and notices must necessarily be brief. 



Fasciola. — As I have elsewhere urged, the common hver fluke 

 ought not to be placed under the genus Bistoma, its proper generic 

 title being Fasciola, as first proposed by the illustrious Linneus 

 (1767), and subsequently adopted by F. MuUer (1787), Brera 

 (1811), Ramdohr (1814), and others. Unfortunately, Eetzius 

 (1786) and Zeder (1800) changed the generic appellation without 

 good cause, and the majority of writers, following their authority, 

 refase to employ the original name, notwithstanding that the dis- 

 tinctive types of structure displayed by the two genera, respectively, 

 demand the retention of the Linnean title. A glance at the 

 arrangement of the digestive apparatus, as shown in a fascicle I dis- 

 covered in the Giraffe (1854), exhibits a marked deviation of the 

 simple distome type (see Frontispiece). I have now publicly, for 

 several years past, and at regular intervals (1854-56-58-60-62), 

 strongly urged a final adoption of the Linnean nomenclature, the pro- 

 priety of this view having been previously advocated by Blanchard. 

 I think it would even be preferable to abandon the genus Distmna 



