182 TAPEWORMS OF HARES AND RABBITS STILES. VOL.XIX. 



Neck very short and broad. Segmentation visible 0.5G mm. from ante- 

 rior extremity of the head. The proglottids rapidly become distinct, and 

 in the specimens at hand the posterior border of each segment overlaps 

 the anterior border of the next following segment for about one-third 

 of its length in the anterior segments to one-sixth of its length in the 

 posterior segments. The genital aiilagen become visible almost imme- 

 diately after the segmentation. The genital pores are double and 

 opposite in about the middle of the lateral margin. Male organs : The 

 testicles are numerous and are scattered over the entire dorsal portion 

 of the median field, but do not quite reach the lateral canals; in tbe 

 middle portion of the median field they extend farther ventral than in 

 the lateral portion. The cirrus pouch lies dorsal and slightly posterior 

 to the vagina, on both sides of the segment; it is 0.24 mm. long by 96^ 

 broad (proximal end) ; it is relatively muscular; the lateral portion is 

 narrow, but the proximal portion is swollen to contain a globular 

 vesicula seminalis; the vas deferens coils and curves from here median 

 and cephalad, the convexity of the curve being distal. Female organs : 

 The female glands lie in the median field, about halfway between the 

 median line and lateral canals ; they were not analyzed in detail ; details 

 of the development of the uterus must also be left to some one who can 

 obtain further material; the vagina lies ventral and slightly proximal 

 to the cirrus-pouch on both sides of the segment; it is narrow, 19 mm. 

 long, and extends to a point slightly dorso-median of the ventral canal, 

 where it swells into an enormous receptaculum seminis which occupies 

 the ventro-lateral portion of the median field, and in some sections 

 measures 0.72 mm. long by 0.19 mm. broad; median of this organ and 

 ventral of the testicles are situated the female glands; there is appar- 

 ently a common uterus to both ovaries; it is situated vent-rally of the 

 testicles at the height of the genital pores, but proximally and distal ly 

 of this plane it extends farther dorsad: sections on other planes than 

 that of the pore show that dorso- ventral trabecuhe of the body stroma 

 divide the uterus into numerous pouches, although sections at the 

 pores generally show a more or less continuous transverse stem; the 

 ova are unusually small, measuring 32 to 36 // in diameter; the bulb 

 of the pyrifonn body varies between 8 // and 12 //; the horns are 

 relatively long and crossed. Excretory and nervous systems: At the 

 height of the genital pores the dorsal canal lies between the ventral 

 canal and nerve; in other planes it may lie dorsal of the ventral canal. 

 The genital canals pass dorsally while the uterus passes vent-rally of 

 the longitudinal canals and nerves. 



As specific name, I proposed prwcoquis (misprinted as prwcoquus in 

 the original description), referring to the unusually early development 

 of the genital organs. The following is proposed as a specific diagnosis : 



Diagnosis. Cittotcenia prcccoqiiis (Stiles, 1895), Stiles & Hassall, 

 189G. Strobila attains about 40 mm. in length by 5.5 mm. in breadth 

 by 0.72 mm. in thickness; the posterior 10 mm. is slightly narrowed. 



