359] ANOPLOCEPHALIDAZ—DOUTHITT 9 



sexual maturity to longer than broad in the case of ripe proglottids. 

 The length of the scolex is roughly 560/x. The greatest width, 350/*, is 

 reached 95/a from the anterior end. The anterior end is rounded; 

 posteriorly the scolex narrows regularly. 



The genital pores are all on the right margin near the middle of 

 the proglottid. The circular muscles surrounding the inner end of the 

 cirrus pouch are usually contracted, compressing this part and making 

 the pouch inversely pear-shaped. In older proglottids however the 

 inner end becomes distended and much larger than the outer. In some 

 specimens the cirrus pouch is separated by a distance equal to its own 

 length from the ventral excretory duct ; in others its median end extends 

 across both ducts (Figs. 5 and 8). The different conditions do not 

 seem to depend so much on the stage of contraction of the proglottid 

 as upon differences in the position of the excretory ducts. An internal 

 vesicula seminalis is present. The cirrus is generally extruded, tho 

 usually it does not extend outside the genital pore. 



The vas deferens is not enlarged and is not coiled, tho it is probable 

 that some coiling would be found in more expanded specimens. A 

 distinct prostate gland is present ; it is tubular with a globular enlarge- 

 ment at its end. Lateral to the pore of the prostate gland the vas 

 deferens is surrounded by a loose cellular mesh. The testes are all 

 dorsal. On the left they may extend across both excretory ducts, or 

 they may be strictly limited to the median field. To the right they 

 extend as far as the prostate gland in the anterior part of the field. 

 They extend distad as far as the vitelline gland and receptaculum 

 seminis, and on the left of these they extend to the distal end of the 

 proglottid. The number varies in eight proglottids counted from 24 

 to 41. They are mostly tranversely elongated, 55 to 80 fi long in trans- 

 verse axis by 30 to 50/x in longitudinal axis. 



The vagina lies entirely posterior to the cirrus pouch and vas 

 deferens and in the same plane. Up to the beginning of the receptacu- 

 lum seminis its walls are glandular. The receptaculum begins where 

 the vagina crosses the dorsal excretory duct; it enlarges gradually and 

 uniformly to near its inner end then becomes abruptly smaller. The 

 ovary is an asymmetrical mass most of whose bulk lies on the pore side, 

 but it approaches no nearer to the excretory ducts on one side than on 

 the other and the oocapt is as often to the left as to the right of the 

 median line. It shows rather obscure and uncertain evidence of partial 

 division into about seven radiating lobes. The lateral and median lobes 

 of the vitelline gland are but little larger than the transverse portion 

 of the gland which connects them. This gland lies considerably to the 

 pore side of the median line. 



