38 PROCEEDINGS OF THE NATIONAL MUSEUM vol.70 



about the middle of the margin of a proglottis ; cirrus long and fili- 

 form, rigid, from a clubshaped thin-walled base (fig. 111). Dia- 

 meter of basal portion, at its outer end, 0.024 mm., of filiform portion 

 0.002. ; cirrus-pouch cylindrical, extending beyond the median line of 

 the proglottis, its inner portion acting as an outer seminal vesicle ; an 

 inner seminal vesicle lies along the dorsal side of the cirrus-pounch ; 

 testes three, one on the poral side of the median line, two on the 

 antiporal side, oval, about 0.048 by 0.060 mm. in diameter. Ovary 

 on median line, small, four-lobed when fully developed; vitelline 

 gland small, compact, dorsal to the posterior border of the ovary, 

 becoming two-lobed ; uterus ; at first lobed, later occupying nearly all 

 the interior of the proglottis, and crowding the persistent cirrus to 

 the anterior border of the proglottis; diameter of onchospheres, so 

 far as they can be seen in whole mounts, about 0.018 mm. 



In a strobile from which the scolex is missing, measuring 13 mm. 

 in length, rudiments of male genitalia appear in the anterior pro- 

 glottides, which are 0.04 mm. in length and 0.15 in breadth. The 

 male genitalia are mature 4 mm. from the anterior end. Rudi- 

 ments of the ovary can be seen about 3 mm. farther back. The 

 vitelline gland persists in a few proglottides after the uterus has 

 become prominent. In the last 3.5 mm., comprising 21 proglottides, 

 the uterus fills practically all the interior of the proglottides except 

 at the anterior border where the long, cylindrical cirrus-pouch lies. 

 In the preceding eight proglottides the uterus is distinctly lobed, 

 and occupies a large part of the interior of the proglottides. The 

 uterus in the next 12 preceding proglottides is lobed, but less and 

 less developed anteriorly. The ovaries become inconspicuous shortly 

 after the uterus appears, while the vitelline glands persist for about 

 12 proglottides after the ovaries can no longer be recognized. In 

 an examination of serial sections the vagina was seen to begin as 

 a short, slender tube with a sphincter muscle at its inner end. A 

 short distance from the sphincter the vagina expands into a seminal 

 receptacle which lies along the ventral side of the cirrus-pouch. 

 The inner seminal vesicle communicates with the cirrus-pouch, which 

 in large part functions as a seminal vesicle, by a short vas deferens. 

 A portion of this inner seminal vesicle projects beyond the inner 

 end of the cirrus-pouch, but the greater portion of it lies on the 

 dorsal side of the cirrus-pouch. The structure of the cirrus-pouch 

 agrees with descriptions of H. timer acanthos. The long and filiform 

 cirrus was clearly demonstrated in serial sections. 



