TRANSACTIONS 



OF 



THE \EW YORK M^OSCOPICAL SOCIETY. 



JANUARY, 1879. 



MECHANISM BY WHICH ECHINORHYNCHUS 

 ANCHORS HIS SNOUT. 



BY J. D. HYATT. 



EchinorJiynchis is a genus of Entozoa, of the natural order 

 Acanthocephala^. 



These formidable parasites inhabit the alimentary canal 

 of fishes, and the one upon which my observations have 

 been made is probably Echinorhynchiis fusiformis, found in 

 the intestinal canal of the lake white-fish. These fishes are 

 brought to the New York market in the fall and winter, and, 

 thinking that I might possibly find some interesting micro- 

 scopical objects from the bottom of the lakes, I carefully 

 examined the stomach and intestines of several of these fishes 

 obtained at Fulton Market in the month of October ; but if 

 these organs had been carefully washed they could not have 

 been more completely destitute of every semblance of food. 

 The intestinal canal, however, was uniformly lined with these 

 parasites, with their snouts so thoroughly anchored in the tis- 

 sues that they would sometimes suffer themselves to be pulled 

 asunder rather than let go their hold ; for although the fish 

 had probably been several days out of the water, these para- 

 sites were always alive. 



Placing some of them in water under the microscope, I had 

 an opportunity of observing the manner in which they man- 

 age to anchor their snouts so firmly; for when detached they 

 constantly repeat the exercise by which this is accomplished. 

 The snout is first slowly retracted, by inverting it, or turning 

 it outside in, until nothing appears beyond the body but the 



