346 BENEDICT. [Vol. XVI. 



concave margin of the last proglottis, which resembles a sieve. 

 The longitudinal vessels in this proglottis terminate in small 

 sinuses, which branch and anastomose, much like the ducts in 

 the scolex, but more irregularly. This network of ducts is 

 in communication with the exterior by means of a multitude 

 of pores which are found at this place (PI. XVI, Fig. 13). 



Such a posterior outlet differs from any previously described, 

 since there is no terminal muscular reservoir. The tendency 

 of the Proteocephali to the formation of excretory complexes 

 is very well illustrated by this form. 



Directly beneath the apex of the scolex is a sac of cuticular 

 structure enclosing a small number of circular masses, closely 

 pressed together (PI. XVI, Fig. 3, ca). The masses seem to 

 be of a calcareous nature, and are penetrated by numerous fine 

 canals. No connection whatever could be traced between this 

 sac and any outside system, although the excretory ducts form 

 a thick network about it, I have found no mention elsewhere 

 of such a structure, which is different in many respects from 

 the simple calcareous bodies common among cestodes. 



Sexual Oi'gans. — The genital sinus, as before stated, is 

 irregularly alternate in position, and is situated on the margin 

 about one-fourth of the length of the proglottis from the ante- 

 rior end. It resembles in position and relative size that of P. 

 fossata, P. abscissa, and Corallobothriiim lobostim (Riggenbach, 

 '96). In P. tonilosa and P . filicollis, as described by Kraemer 

 ('92), no common genital sinus is present, and the genital open- 

 ings are exactly in the middle of the margin. The vagina 

 opens directly in front of the male opening, a characteristic of 

 the Proteocephali. 



The Male Getiital Organs. — The testes are from seventy- 

 five to one hundred in number, arranged irregularly through- 

 out the space within the longitudinal muscles of the proglottis 

 (PI. XVI, Fig. 9, /.). Such a position and number is described 

 as obtaining in P. tonilosa, P. filicollis, P. abscissa, P. fossata, 

 Corallobothrium lobostmi, and many others which have been 

 less accurately described. When the uterus becomes distended 

 the testes are crowded to the ventral surface, and the uterus 

 lies in a broad irregular sheet above them. The testes are 



