372 University of California Publications in Zoology. [ V L. 6 



greater size in G. fimbriata than in G. urna, and its folds many 

 times as complex, but generally held in a position exactly like that 

 shown in Wagener's second figure, that is, the opening of the 

 funnel, the rosette surface, lying, not at right angles to the sur- 

 face of the body, but parallel to it. 



The .stage shown in Wagener 's first figure represents the most 

 extreme stage of expansion noted by the writer. No stages corre- 

 sponding to those figured by Lonnberg (pi. 33, figs. 1-4) were 

 seen, although the specimens observed were in many cases per- 

 fectly fresh and very active, contracting and expanding with 

 great freedom, and moving about in the dish. But the shape of 

 the posterior rosette was never materially altered, nor did the 

 lateral folds completely disappear. Further, in the observations 

 by Wagener, by Dr. Kofoid, and by the writer on the worm, an 

 expanded condition always involves expansion of the acetabular 

 extremity as well as the neck of the rosette. None of Lonnberg 's 

 figures shows anything suggesting the very characteristic aceta- 

 bular extremity as first figured by Wagener. In observations of 

 twenty-three living worms the writer has never failed to find the 

 acetabular extremity assuming and maintaining this appearance 

 throughout the period of activity. Lonnberg 's observations, as 

 above noted, are corroborated by Olsson (1896), who adds the 

 astonishing statement that the worms preserve this form in 

 alcohol. As the parasite is exceedingly sensitive to chemical 

 stimuli, and invariably reacts to even a very dilute solution (5 

 per cent.) of alcohol by strong contraction, this seems to indicate 

 that Olsson at least was dealing with some form other than 

 Gyrocotyle. The writer found on two occasions, while searching 

 for Gyrocotyle in Chimaera colliei, a distome strongly suggesting 

 Lonnberg 's figure and maintaining its shape in killing fluids, 

 which might have been mistaken for Gyrocotyle. But since Lonn- 

 berg states explicitly that these transformations in form took 

 place under his eyes, this explanation seems scarcely possible. 

 We are forced to accept a discrepancy in results here, only to be 

 removed by further investigation. 



The living worm, in the intestine of a fish that has just been 

 caught, is translucent, of a dull pink color, exactly similar to 

 the intestine on which it lies. The worm in perfectly fresh fish 



