18 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 64. 



such a degree that the subcuticiila is reduced, in transverse sections, 

 to a narrow line. Next the cuticle the subcuticula is dense. 



The longitudinal excretory vessels are rather remote from the 

 lateral margins. In a transverse section, 4 mm. in the longer diam- 

 eter, which represents the breadth of the strobile at that point, the 

 longitudinal vessels were 0.86 from the lateral margins. In the same 

 section the lateral nerve was 0.28 from the lateral margin. No trace 

 of circular muscles was seen. 



Rejrroductive organs. — The cirrus-pouch is long-pyriform, and lies 

 near the anterior border of the proglottis. It opens by the common 

 genital pore on the lateral margin near the anterior end of the pro- 

 glottis. The cirrus is long and slender, and covered Avith v^vy dense, 

 liair-like spines. The vas deferens is voluminous, and lies between 

 the median end of the cirinis-pouch and the uterus. The testes oc- 

 cup3'' the median portion of the parenchyma, extending laterally 

 nearly to the nerve. They are continuous along the median axis of 

 transverse sections of the anterior end of a proglottis, but are inter- 

 rupted by the ovaiy, and, in ripe proglottides, by the uterus. In 

 transverse sections they form a single slightly irregular row toward 

 the margins, becoming irregularly two-ranked for a short distance 

 near the middle of sections made in front of the uterus. 



The vagina entere the conmion genital cloaca from the anterior 

 side. In a series of sagittal sections the genital cloaca was estimated 

 to be 0.2 mm. deep. Tlie vagina is a thin walled tube at first lying 

 along the anterior border of the cirrus-pouch, and the coils of the vas 

 deferens. In its earlier portion it is lined with fine hair-like spines 

 similar to those of the cirrus but shorter. It is compressed, at first 

 dorso-ventrally, then antero-posteriorly (figs. 24^29). Toward the 

 median axis of the proglottis it becomes tubular for a short distance, 

 then, in most cases, it was comj^ressed again in the vicinity of the 

 uterus. At the median axis it turns toward the posterior and follows 

 the uterus, being partly enclosed in the uterine walls, in a tortuous 

 course on the dorsal side. Before joining the germ duct it enlarges 

 to become the seminal receptacle, which lies, in about two close coils 

 at right angles to the long axis of the proglottis. The complex 

 formed by the ducts of the genitalia in the vicinity of the shell gland 

 is compact, and difficult to reconstruct from the sections. A provi- 

 sional interpretation is given in Figure 30. The ovary is at the 

 posterior end of the proglottis and consists of two main divisions 

 symmetrically placed, the one dorsal and the other ventral, each be- 

 ing distinctly lobulate. 



The vitellaria make a distinct layer of the extra-parenchymatous 

 region of the proglottis immediately within the layer of longitudinal 



