6 PROCEEDIK-QS OF THE NATIONAL MUSEUM. vol.60. 



Scolex. — ^Details of structure are shown in figures 2 and 3. The 

 bothria are large and flat, and have thick, entire margins. The an- 

 terior edge is not reflected, and is even but shghtly projecting. The 

 median margins of a pair fuse together near the anterior ends. In 

 front view the suckers are prominent, the anterior shelf-Hke projec- 

 tion being represented only by the thickened semicircular border 

 of a sucker. There is lacking the groove at the posterior edge of the 

 bothria and the pseudo-hooklets at the angles. In one of the speci- 

 mens the outline of the anterior end is elevated in the middle on 

 account of raised median angles of the bothria. This seems to be a 

 contraction character, as in the other two specimens the front ends 

 are flat and practically at right angles to the axis of the scolex. 



The breadth of each of the three scoleces in front is 6.5 mm., and 

 the thickness of each is 4 mm. In one the breadth of a bothrium is 

 3 mm. and the length 7 mm. ; in another the breadth is 4 mm. and 

 the length 7 mm.; in the third the breadth is 5 mm. and the length 

 9 mm. In each of these three scoleces the bothria are nearly parallel 

 with the axis of the scolex, and all are rather shallow and plate-like. 

 This is in contrast with the prevailing cup-like character and widely 

 flaring position of the bothria in D. plicitum. 



Strobile. — The superficial characters of the strobile have already 

 been described. The most outstanding features are the relative short- 

 ness of the proglottides, the linear habit of the strobile, and the de- 

 velopment of longitudinal furrows, the most conspicuous being a 

 median furrow on one of the flat surfaces (ventral) , especially notice- 

 able in the anterior region. Transverse sections made through un- 

 ripe sections show a striking waist-like constriction at about the 

 middle, indicating a median furrow on both the dorsal and ventral 

 sides. The shortness of the proglottides as compared with the breadth 

 persist even to ripe ones filled with eggs, which are still only from 

 one-tenth to one-sixth as long as they are broad. This is in marked 

 contrast with Beneden's figure of D. septana, in which the proglot- 

 tides are represented as becoming squarish, and even longer than 

 broad, toward the end of the strobile. 



Anatomy of proglottis. — The different layers of the wall are not 

 sharply marked off from each other. The cuticle in adult segments 

 is thin. The limits between the subcuticula and the layer of longi- 

 tudinal muscle fibers is not clearly defined, but in a series of sections 

 stained in indigo-carmine, in which the muscles came out a bright 

 blue, and the granular bodies in the subcuticula appeared as red dots 

 on a pale blue field, the two layers were fairly well differentiated. 

 It was noticed that the subcuticula at one region of the sections con- 

 tained numerous relatively large glandular bodies which lay imme- 

 diately under the cuticula (figs. 8 and 10 scg.). An examination of 

 series of sections, both transverse and sagittal, revealed the interest- 



