NEW SPECIES OF HYMENOLEPIS. 



2 39 



vessels on each side, dorsal and ventral. In the posterior segments the 

 latter is much wider than the former ; in the neck region both are 

 of about equal width. The two vessels run separated from the lateral 

 margin of the same side by a distance equal to about 1/6 the breadth 

 of the segment containing them. 



2. H y menale pi s inermis n. sp. 

 Pl. VIT., figs. 11-16. 



This new species is also from the duodenal parts of the intestine 

 of chickens reared up in or about Tokyo. Numerous specimens were 

 collected on April 9 (1906), April 23 (.1907) and Oct. 3 (1907). 



Diagnosis. 



Length 5-10 mm. Rostellum very small, globular. Head globular, 

 0.15111m. long and broad. Suckers oval, 0.07 min. by 0.04 mm. Neck 

 may be extended to 0.3 mm. length by 0.05 mm. thickness. Segments 

 gradually increase in size posteriorly ; largest segments 0.06 mm. long 

 and 0.35 mm. broad. Genital pores unilateral. Cirrus pouch pyriform, 

 shorter than half the breadth of segment. Three testes dorsal to 

 female glands, one on porose and two on aporose side of the median 

 line. Female glands forming a mass in median ventral position. Seminal 

 receptacle in a line along porose side of segments. Vagina short, thin. 



Description. 



External characters. — All the specimens on hand are small but 

 fully mature, measuring 5-10 mm. in total length. The segments 

 number 1 50 or more ; of these about one-fifth in the posterior parts 

 are ripe and contain onchospheres. The segments are all and always 

 broader than long, gradually increasing in dimensions posteriorly. 

 Segments of the middle parts 0.05 mm. long and 0.25 mm. broad 

 Largest segments in the posterior parts 0.07 mm. long and 0.35 mm. 

 broad. 



