182 TAPEWORMS OF HARES AND RABBITS— STILES. 



l!^eclv very sliort and broad. Segmentation visible O.riO mm. from ante- 

 rior extremity of the head. The proglottids rai)idly become distinct, and 

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

 the anterior border of the next foHowing segment for abont one-third 

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

 posterior segments. The genital anlageu become visible almost imme- 

 diately after the segmentation. The genital ])ores are double and 

 opposite in about the inidiUe of the lateral margin. Male organs: Tlie 

 testicles are numerous and are scattered over the entire dorsal jtortioii 

 of the median held, but do not <piite reach the lateral canals: in the 

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

 the lateral j)ortion. The cirrus jwuch lies dorsal and slightly posterior 

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

 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 lialfway 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, 1!) mm. 

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

 where it swells into an enormous receptaculum seniinis which occupies 

 the ventrolateral portion of the median field, and in some sections 

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

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

 ently a common uterus to both ovaries; it is situated ventrally of the 

 testicles at the height of the genital pores, but i)roxiinally and distally 

 of this plane it extends fartlier dorsad; sections on other planes than 

 that of the pore show that ilorso-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 3() // in diameter; the bulb 

 of the pyriform body varies between 8 ft and 12 /•■; the horns are 

 relativelj' long and crossed. Excrettn-y and nervous systems: At the 

 height of the genital pores the dorsal canal lies l)i'twcen the ventral 

 canal and nerve; in other i)lanes it may lie dorsal of the ventral canal. 

 The genital canals pass dorsally while the uterus ])asses ventrally of 

 the longitudinal canals and nerves. 



As specific name, I proposed pra'cotixis (misprinted as praroquus in 

 the original description), refening to the unusually early development 

 of the genital organs. The fi>llo wing is ])roposed as a specific diag'uosis : 



Diagnosis. — Ciitoiwnia prwcoipth (Stiles, ISO.l), Stiles vK: Hassall, 

 180<). Strobila attains about 40 mm. in length by ."i.5 mm. in breadth 

 by 0.72 mm. in thickness; the i)osterior 10 mm. is slightly narrowed. 



