356 BENEDICT. [Vol. XVI. 



of an oviduct leading from it to an ootype — a duct with a mus- 

 cular coat. The lateral position of the vitellaria, the elongated 

 acinous structure, and the ducts which proceeded from them 

 to the ootype were described. The uterus was shown to be 

 a thin-walled sac with lateral branches in the median line of the 

 proglottis. A shell gland was demonstrated surrounding the 

 ootype. He pointed out the number and scattered position of 

 the testes, and the ducts which collected the spermatozoa. He 

 also showed that these ducts unite to form the vas deferens, 

 which is coiled in the center of the proglottis, and functions as 

 a seminal vesicle. Finally he described the termination of the 

 vas deferens in a muscular cirrus, enclosed in a well-developed 

 cirrus pouch. These characteristics show it to be a typical 

 species of Proteocephahis. 



The specimens which I received from Dr. Ward's collection 

 were in four lots, two of these having been taken from Core- 

 gomis nigripiimis, one from C. prognatJms, and one from C. artedi. 

 They were obtained by Dr. Ward while in charge of a bio- 

 logical examination of Lake Michigan, under the auspices of 

 the Michigan Fish Commission, during the summer of 1894, 

 All of the fish were caught in the Traverse Bay region, near 

 Charlevoix, Mich. The cestodes were found in the stomach 

 of C. artedi, and of one specimen of C. nigripinnis, and in 

 the intestine of C. prognathus and of the other specimen of 

 C. 7iigripinnis . 



General External Morphology . 



In external form those from C. artedi and C. prognathus were 

 alike (PI. XVI, Fig. 21), while those taken from C. nigripinnis 

 were longer than the first, and the neck was not only much 

 longer, but also slenderer (PL XVI, Fig. 22). In the shorter 

 specimens the length varied from 12 mm. to 16 mm., while the 

 breadth at the widest point was .8 mm., and the neck was about 

 two-fifths the total length of the body. In the other form the 

 length varied from 15 mm. to 25 mm., the breadth was .8 mm., 

 while the neck ranged from three-fifths to four-fifths of the 

 entire body length. In one of the two lots which came from 

 C. nigripinnis was a specimen very much larger than the others. 



