26 JOHN E. GUTBERLET 



well as those on the outer edge of the sac, bear long processes. The 

 outer layer of the rostellar sac is composed of longitudinal and 

 oblique fibers of a muscular nature which probably have for their 

 function the movement of the rostellum. 



The four excretory canals, that have extended forward through 

 the entire length of the body, unite in the scolex to form a ring 

 (Fig. 3, e.v), which lies in the tissue of the rostellar sac around the 

 body of the rostellum. 



The suckers are prominent. They are oval in shape and in 

 preserved specimens measure 180 to 210/^ in length and from 135 

 to 175jM in extreme breadth. In the center of each sucker there is 

 a depression or an acetabulum, 30 to 40/^ in diameter. The entire 

 inner surface of the suckers possesses minute booklets or spines 

 (Fig. 4) 1.5 to 2(1 long. These booklets not only line the suckers 

 but also extend over the entire surface of the scolex (Figs. 3, 5) 

 and down onto the neck region ; they disappear before reaching 

 the first segment. They appear more distinctly on scolices that are 

 somewhat contracted than on those that are well extended. These 

 booklets can be seen only in sections as they are too small to be 

 distinguished readily in whole mounts. 



Musculature: The longitudinal muscle fibers are arranged in 

 bundles which are scattered, forming a loose irregular layer. The 

 bundles are numerous and nearly of a uniform size. There are no 

 transverse muscle fibers present except a few minute oblique fibers 

 which connect some of the longitudinal fibers near the ends of the 

 proglottids. Some dorso-ventral fibers are present, but they are 

 not abundant. 



Nervous System: The longitudinal nerve fibers are arranged 

 in fiber tracts which approach the structure of a nerve cord. The 

 individual fibers do not form a compact mass, but are more or less 

 free in the tract. Nerve cells have no definite arrangement, but 

 are situated irregularly along the fiber tract (Fig. 6). The nerve 

 cells are somewhat spindle-shaped and quite large, being from 20 

 to 25,a long by 6 to 8/x wide with large nuclei. Transverse nerves 

 are composed of individual cells with long processes extending 

 transversely from the lateral fiber tracts. The transverse fibers are 

 much scattered and have no definite arrangement except that they 



