PARASITOLOGY. 91 



from one-half to three-fourths of an inch in length. 

 The tail of the male is coiled in a spiral 

 manner. This extremity is provided with ^ ^b 

 two unequal spiculae and five anal papillae. (^ 



The tail of the female is straight and ob- fi?. si.-spi- 

 tuse; the vulva is situated near the ante- /optera 



Megastoma. 



rior third of the body ; the female is ovo- a, Male, 

 viviparous. The head is provided with b, Female, 

 four thick lips. 



Animal Infested. — The horse. 



Parts Infested — Conditioyi Prodicced. — The worms are 

 found in the stomach of the horse, where they cause 

 tumors ; the larvae find their way into the ducts of 

 the gastric glands, where by their presence they pro- 

 duce sub-mucous tumors ; these tumors develop until 

 they are as large as pigeon's eggs and round or oval 

 in shape, and the cavity of the tumor may contain 

 dozens of the worms; an opening communicates 

 with the interior of the stomach. The color of the 

 mucous membrane over the tumor does not differ 

 from that of the remainder of the mucous surface. 



hijury to Host. — When found usually only one or 

 two tumors are present, and no serious disturbance 

 has been noted. 



Spiroptera Microstoma (Micro — small ; stoma — mouth) . 

 Distributio7i. — Found frequently in the 

 United States and in Europe. 



Descriptio7i. — In shape and color this 

 worm resembles the preceding one. The 

 Fig. 32 -Spi- male is about one-half inch long, the fe- 



ROPTERA 



Microstoma, male three-fourths. The tail of the male 

 b, Female, is coiled in a spiral manner ; the tail of 



