40 



BULLETIN ,69, UNITED STATES NATIONAL MUSEUM. 



2.5 mm. behind the head in 

 which the male organs had 

 just reached the functional 

 stage measured 30/a in length 

 by 120|u, in width. 



The genital pores are uni- 

 lateral on the right-hand mar- 

 gin of the strobila, located 

 slightly in front of the middle 

 of each segment. 



^■ 



Internal anatomy. 



The cirrus pouch and semi- 

 nal vesicle are dorsal of the 

 excretory vessels. 



Afale reproductive organs. — 

 The testicles are three in num- 

 ber, dorsally located one on the 

 right-hand side and tw^o on the 

 left-hand side of the segment. 

 They reach a maximum size of 

 25/A in diameter. A seminal 

 vesicle is present in the an- 

 terior portion of the segment 

 near the median line; it at- 

 tains a size of 25 to 45)u, in 

 diameter. 



The cirrus pouch is elon- 

 gated, tapering toward its 

 outer end, and measures 75 to 

 95/x in length by 12 to 18/x in 

 diameter. Its inner end is 

 near the anterior border of 

 the segment and extends be- 

 yond the median line in the 

 younger segments. The outer 

 wall of the pouch is thin with- 

 out definite muscle elements. 

 Within the pouch the vas 

 deferens is enlarged to form a 

 seminal reservoir, which occu- 

 pies more or less of the cavity 

 of the pouch. 



