TiENIOID CESTODES OF NORTH AMERICAN BIRDS. 



35 



long as broad. The genital pores are irregularly alternate at about 

 the middle of the segment. The genital sinus is deep and narrow. 



Internal anatomy. 



The ventral excretory canals are connected in the posterior portion 

 of each segment by a transverse canal. 



The longitudinal muscles are arranged in two concentric layers, the 

 inner layer {int. muse.) consisting of about 50 bundles, the outer {ext. 

 muse.) of more numerous smaller bundles. Well-defined transverse 

 fibers are present just inside the inner longitudinal layer. Dorso- 

 ventral fibers are very weakly developed. 



The sexual canals pass on the ventral side of the excretory vessels 

 and the nerve. 



d.ex. 



ext. inuac. 



ov. y.g. 



lOQ^x. 



Fig. 27. — Anonchot^nia globata : Sexually matuke segment, transverse section. 

 c. p. J Cirrus pouch, d. ex.. Dorsal excretory vessel, ext. muse. Outer longi- 

 tudinal MUSCLES, int. muse. Inner longitUdIn'al muscles. I. n.. Nerve cords. 

 ov.. Ovary, t.. Testicles, vag.. Vagina, i;. ex.. Ventral excretory vessel, y. g.. 

 Yolk gland. 



31 ale reproductive organs. — The testicles (t.) are five in number 

 located toward the dorsal surface in the anterior portion of the seg- 

 ment. They measure when fully developed 30 to 40/^ in diameter. 

 The vas deferens is somewhat tortuous, without, however, forming a 

 mass of coils, and is without vesicular enlargements. The cirrus 

 pouch ((?. p.) broadest at the base and tapering toward the end, 

 measures from 70 to 80/i, in length by '25fx in diameter. Colin de- 

 scribes the cirrus pouch as short, club-shaped, and " recht muskulos." 

 In my specimens the outer wall of the pouch is thin, with weakly 

 developed musculature. 



