jiuT. rz. A NEW CESTODE FROM SHAEKS LINTON. 6 



mm. in length; the length of the first of the series was 0.77 nmi., its 

 breadth 1.19 mm. ; length of penultimate segment 1.05 mm., breadth 

 1.05 mm. Length of last segment 1.82 mm., breadth 0.98 mm. near 

 anterior end, tapering to 0.5 mm., near posterior end. A free, 

 ripe segment, mounted in balsam, has the following dimensions: 

 Length''7 mm.; breadth at anterior end 0.42 mm., at level of genital 

 pore (maximum) 2.10 mm., near posterior end 0.42 mm. Dimen- 

 sions of a free segment in which ova had not begun to develop: 

 Length 4.5 mm.; breadth near anterior end 0.50 mm., at level of 

 genital pore (maximum) 2.27 mm., near posterior end 0.77 mm. 

 ^ The musculature of the strobile is weak. Beneath the cuticuhir 

 layer there is a layer of longitudinal muscles, the fascicles of whicli 

 are flat and ribbon-like, with the long axis of their section at right 

 angles to the surface. The fibers are very fine. In a transverse 

 section near the scolex the thickness of the muscular layer was about 

 one-ninth the shorter diameter of the section. A diagram of the 

 muscle layer is shown in figure 10. No circular muscles were noted 

 in any of the sections. 



The cuticle in sections near the scolex is smooth, but farther back 

 becomes transeversely rugose. This condition is best seen in sag- 

 ittal sections (fig. 13). 



Reproductive organs. — The genital pores are on the lateral mar- 

 gins, irregularly alternate, and, in adult 'segments, situated at about 

 the anterior third. 



Male.—i:hQ cirrus is long, tapering, and spinose. The cirrus 

 pouch has rather weak walls, and lies on the posterior side of the 

 horizontal portion of the vagina. In adult, but unripe, joints the 

 retracted cirrus lies in several folds in the pouch. Beginning at 

 the genital pore it passes postero-mediad at an angle of about 45 

 degrees with the lateral margin, then becomes slightly tortuous, and 

 continues antero-mediad as the vas deferens, which forms voluminous 

 folds about the anterior curved portion of the vagina. 



The testes are distributed along the mid region of the proglottis, 

 from a point approximately midway between the anterior end and 

 the curve of the vagina, to the anterior border of the ovary, and 

 occupy about one-half the width of the proglottis. 



Female. — The vagina opens at the genital pore in front of the 

 cirrus. Its course is at first antero-mediad to near the median line, 

 where it turns abruptly posteriad to follow the median line until 

 near the posterior end of the proglottis, where it joins the germ duct, 

 ^ear the exterior it is slightly constricted; beyond the constriction 

 it enlarges rather abruptly, then tapers more slowly to the curve, so 

 that the portion which is directed antero-mediad is fusiform. At 

 the curve and along the median line the diameter is reduced and 

 remains nearly uniform. The course along the median line is nearly 



