50 PROCEEDINGS OF THE NATIONAL MUSEUM vol.70 



rounded in outline, the suckers nearly circular and but little promi- 

 nent. There is a short rostellum surmounted by a double circle of 

 very short hooks. Their exact number was not satisfactorily made 

 out, but there appear to be in the neighborhood of 40 (this from 

 notes made on fresh material) ; in the mounted material the number 

 of hooks appears to be less than this estimate, and they are so closely 

 crowded that there appears to be but a single circle; the length is 

 about 0.01 mm. 



Strobile. — There is a neck which, as a rule, is considerably longer 

 than the scolex. One case was observed in which the distance to the 

 first segments was about equal to the length of the scolex, the short 

 neck being of about the same diameter as the scolex. In the other 

 strobiles the diameter of the neck was less than that of the scolex. 

 The segmentation begins gradually, the first segments being much 

 broader than long. The segments lengthen until, toward the poste- 

 rior end of the strobile, they are longer than broad. The segments 

 overlap but slightly, and the breadth of the anterior end is less than 

 that of the posterior, except at the posterior end of the strobile, 

 where they may be nearly linear, the extreme posterior segment being 

 rounded and slightly narrowed at the posterior end. The genital 

 pores are irregularly, alternate, and situated near the anterior fourth 

 of the lateral margin. The cirrus is short and apparently smooth. 

 The cirrus-pouch is small ; in a transverse section of a ripe proglottis 

 its diameter was 0.045 mm., in another 0.051. There are 12 or more 

 testes. The exact number could not be made out in the mounted 

 specimens, and my sections proved to be made through ripe proglot- 

 tides, in which, although a few testes remained, no estimate could 

 be made from them of the number in a mature, unripe proglottis. 

 The diameter of a single testis in these sections was about 0.05 mm. 

 The vas deferens, as seen in a ripe proglottis, extends from the cirrus- 

 pouch antero-mediad to the median line, where there was a remnant 

 of what appeared to be a coiled mass of the vas deferens, near the 

 anterior end of the proglottis, immediately in front of the para- 

 uterine organ. 



The female genitalia were made out only in part. As seen in the 

 whole mount of a ripe proglottis (fig. 162), the vagina, opening at 

 the posterior side of the cirrus, in the genital cloaca, can be traced 

 in a diagonal line postero-mediad, to a point near the wall of the 

 uterus. Little is shown of its structure, but there is an indication of 

 a slight enlargement into a seminal receptacle. The uterus in most 

 of the ripe proglottides is an elongated sac lying on the median line, 

 and preceded by the para-uterine organ. The latter is filled with 

 dense fibrous tissue. The eggs are oval, with thin membranous 

 shells. The longer diameter of the onchosphere is about 0.03 mm. 



