69S MacCALLUM. [Vol. XV. 



corrected the old statement of the relation in size of the suckers 

 in this form, giving the measurement of the anterior at 0.3 mm., 

 and of the ventral at 0.8 mm. The pigmentation of the intes- 

 tinal coeca and the existence of diverticula were described and 

 a figure given. The main canals and caudal pore, as well as 

 the subcuticular network of the excretory system, were described 

 and the communication with the interstices of the parenchyma 

 emphasized. The genital apparatus was partly worked out — 

 vitellogens, testes, ovary, and a receptaculum seminis were men- 

 tioned, together with another structure situated anterior to the 

 testes of unknown function. This was undoubtedly the cirrus. 

 The measurements of the eggs were given at 0.099 ^n^- t)y 

 0.066 mm. 



Von Linstow (7) in 1883 gave a brief description of the worm, 

 making the measurement of the anterior sucker slightly larger 

 than that of the ventral. He described the quadrangular sac 

 filled with eggs which lies behind the acetabulum, and gave the 

 measurements of the eggs at . 1 1 mm. by .079 mm. He also 

 mentioned the position of the two lobulated testes, the ovary 

 and yolk-gland. His specimens were found in Ardea nycticorax. 



Again (8), in 1886, in his description of some of the Fedts- 

 cJicnko material collected in Turkestan, he described and figured 

 the worm. His description adds nothing to what was known of 

 the anatomy, however, and the figure shows only the suckers, 

 eggs, testes, ovary, part of the intestinal coeca, and a suggestion 

 of the subcuticular excretory canals. 



Stossich (9) in 1892 gave von Linstow's description. 



Since this, Parona, in 1896, has mentioned the worm, but 

 otherwise it has not been noticed. 



My own observations on the anatomy of this form are as 

 follows : Ten specimens were found adhering to the floor of 

 the mouth and sides of the tongue of a great blue heron {Ardea 

 herodias) shot on the Grand River at Dunnville, Ontario, Can- 

 ada. They measured 6-10 mm. in length and 1-2 mm. in 

 breadth during life, although, of course, the measurements vary 

 greatly with the degree of contraction. They are of a dull 

 reddish color, the intestines showing through as brownish black 

 lines, one on each side of the body, and the testes and uterus, 



