TtENIOID CESTODES of north AMERICAN BIRDS. 



49 



The dorsal root measures about 40fx and the prong of the hook about 

 25/x in length. The suckers are 100 to 120 fi in diameter, covered over 

 the entire surface as in Z>. acuminata with regularly arranged mi- 

 nute spines less than 5/x in length. 



y.g. 



lOQu.. 

 Fig. o9.^Diorchis Americana : Sexually mature segment^ at high focus to show 



MALE ORGANS^ DORSAL VIEW, dr., CiRRUS. C. p., CiRRUS POUCH. OV., OVARY. t., TESTI- 

 CLES, ves. sent.. Seminal vesicle, y. g.. Yolk gland. 



As in D. acuminata^ segmentation begins close behind the head, the 

 width of the strobila at its beginning being about 160/a. The segments 

 are broader than long throughout the strobila, and near the posterior 

 end measure 110 to 115/x in length by 500 to 600/x in width. 



vag. 



lOQji. 



Fig. 40. — DioRCHis ambricana : Sexually mature segment^ at deep focus to show 

 FEMALE ORGANS, DORSAL VIEW. OV., OvARY. sem. recept., Seminal VESICLE, vag.. 

 Vagina. ij. g., Yolk gland. 



The genital pores are unilateral on the right-hand margin of the 

 strobila at about the middle of the segment. 



Internal anatomy. 



The nervous system, musculature, and excretory system are as de- 

 scribed above for Diorchis acuminata^ and as in the latter the vagina 



3264— Bull. 69—09 4 



