T.^NIASIS 



175 



suckers; it is prolonged behind by rounded flaps on the upper and lower 

 side. The segments are very short, but wide, the width increasing 

 toward the middle of the length of the body. 



Length, 2.5-3 cm. (1 inch); width, 3-15 mm. (1/8-5/8 of an inch). 



The eggs, by mutual pressure, are polygonal. The shell, as in other 

 Anoplocephalinae, is prolonged by a pyriform point. They are 70-80 

 microns in length. 



It lives in the small intestine and ceemn, more rarely in the colon. 



2. Anoplocephala mamillana (TaBnia mamillana). Fig. 91. 

 Tsniidse (p. 170). — The head is small, somewhat angular, and has a 

 central lineal depression from before to 

 behind. It is provided with oval suckers 

 located upon the side. The segments are 

 nuich wider than long, progressively in- 

 creasing in width from the head. Their 

 length increases toward the posterior ex- 

 tremity, the last segments being about 

 half as long as broad. 



Length, 1-5 cm. (3/8-2 inches); width, 

 4-6 mm. (i<4 of an inch). 



The eggs are elongated and about 88 

 microns in length. 



It infests the small intestine. 



3. Anoplocephala plicata (Taenia 

 plicata). Fig. 91. Ta^niidse (p. 170).— 

 The head is rather large, broader than 

 long, slightly concaved in the center. 

 The four suckers are strong and are di- 

 rected forward. The segments progres- 

 sively increase in breadth and length to 

 the posterior extremity. 



Length, 8-12 cm. (3 1/8-4 ^ inches); 

 width, 8-20 mm. (5/16-^^ of an inch). 



The eggs are polygonal or round and 50-60 microns in length. 



It lives in the small intestine and has been found in the stomach. 



Occurrence. — Horses rarel}' harbor tapeworms. They are said to 

 be most often found in the horses of Russia and to some extent in 

 Germany and other European countries. The most common species is 

 Anoplocephala perfoliata, while of the other two mentioned, Anoplo- 

 cephala plicata is the luore rare. 



Symptoms. — The presence of tapeworms in the intestines of the 

 horse is seldom accompanied by perceivable symptoms. Those general 

 to intestinal helminthiasis, as chronic digestive disturbances, with per- 

 haps anaemia and general unthrift, may accompany the infestation, 





Fig. 91. — Tapeworms of the horse. 

 Left to right: Anoplocephala mamil- 

 lana, A. perfoliata, A. plicata, nat- 

 ural size. 



