176 



PARASITES OF THE DOMESTIC ANIMALS 



though it can only be assumed that these symptoms are caused bj' tape- 

 worms, even though the presence of the worms is made certain by the 

 voiding of the segments. 



Cestodes of Cattle, Sheep, and Goats 



Cattle harbor three species of tapeworms. In all the heads are un- 

 armed. Their larval forms are unknown. 



The three species of tapeworms of cattle also occur in sheep and 

 goats. 



1. Moniezia expansa (Taenia expansa). Fig. 92. Taeniidse (p. 170). 

 The head is small, generally pear-shaped. The 

 suckers are slightly sahent and slit-like. The an- 

 terior part of the chain is filiform. The first seg- 

 ments are very short, those which follow becoming 

 longer, but always much broader than long. The 

 broadest segments may reach a breadth of 2 cm. 

 (^ of an inch). The genital pores are double 

 and located on the lateral margins of the seg- 

 ments. 



The length varies considerably; it may be 15-30 

 feet or more. 



The eggs are globular or polygonal and are 50-90 

 microns in diameter. 



2. Moniezia alba (Taenia alba). Taeniidse (p. 170). 

 — The head is larger than that of the preceding 

 species and is provided with large oval suckers. 

 The neck is short and the segments are longer and 

 narrower than in M. expansa; some may be slightly 

 longer than broad. The width of the broadest 

 segments is about 1 cm. (3/8 of an inch). There 



RaUUetr'^"°^'* ^"""^^ ^^^ *^° genital pores in each segment. 



Its maximum length is about eight feet. 



The eggs are cuboidal and 48-58 microns in breadth. 



3. Moniezia planissima. Taeniidae (p. 170). — The head is nearly 

 square and has slightly elongated suckers. The segments are much 

 broader than long, the ripe ones having a width of 12-26 mm. (3^-1 

 inch). These segments are very thin and semitransparent. Each seg- 

 ment has two genital pores. 



Length, 3-6 feet. 



The eggs are about 63 microns in diameter. 



Thysanosoma actinioides (Taenia fimbriata). Tseniidse (p 170.). — 

 This is a species occurring in sheep, but has not been reported in other 

 domesticated Herbivora. The head is without hooks or rostellum. The 



Fig. 92. — Moniezia 

 expansa, portions of 



