16 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 50. 



Localities. — Brazil, Paraguay, United States (North Carolina; 

 Boulder, Colorado). 



Life history. — The eggs produced by the strobilate tapeworm in 

 the intestine of the primary host pass out and are ingested on food 

 or in water by the secondary host where they develop to form the 



intermediate larval stage or bladderworm, 

 known as Oysticercus macrocystis and 

 very similar to Oysticercus fasciolaris. 

 On ingestion of this bladderworm by the 

 primary host in preying on the secondary 

 host, the terminal vesicle digests off while 

 the head and its strobilate connection with 

 the bladder develops attached segments 

 and so forms the strobilate worm. 



The material 

 recorded here 

 from the 

 United States 

 is in the col- 

 lection of the 

 United States 

 Bureau of Ani- 



FiG.12.- 



-Taenia balaniceps. 

 Aftee Hall, 1910. 



Head. 



mal Industry. 

 That from Lynx rujfus was collected by 

 Doctors Hassall and Graybill from a 

 lynx sent from North Carolina to the 

 National Zoological Park at Washing- 

 ton, District of Columbia, and that from 

 L. haileyi was collected at Boulder, Colo- 

 rado, by Dr. Max Ellis. 



TAENIA BALANICEPS Hall, 1910. 



Specific diagnosis. — Taenia: Head 

 acorn-shaped (fig. 12), 735 tx long by 

 534 to 753 \i. wide. Rostellum rounded 

 and prominent, 307 [x in diameter, and 

 armed with a double crown of 28 to 32 

 hooks, of which the larger are easily lost. 

 The hooks are set far forward of the 

 suckers. The large hooks (fig. 13) are 



145 [JL long. They have a blade of moderate curvature; thfe handle 

 tapers toward its distal extremity; the distal extremity, which is 

 not enlarged, curves slightly dorsad, and in lateral view the ventral 

 outline is slightly convex, while the dorsal outline presents a slight 

 median swelling and another slight swelling at the union of the blade 



Aomm. 

 Fig. 13.— Taenia balaniceps. Labob 



AND SMALL HOOKS. AFTEE HAIX, 

 1910. 



