106 PARASITOLOGY. 



group of worms whose heads are provided with three 

 small lips. The body is rather heavy, and in the 

 female the tail is long and attenuated. The males 

 are provided with spiculae and two pre-anal papillae, 

 and a rudimentary caudal pouch. 



The Oxyuridae are not blood suckers. 



Under the family Oxyuridae is placed the genus 

 Oxyuris. 



OxYURiS CuRVULA (Oxys — pointed ; oura- tail) . 



Syjionym. — Pin worm ; maw 

 worm ; curved Oxyuris. 



Distribution. — Very common in 

 the United States. 



Description. — The body is whit- 

 ish in color and rather thick ; the 

 head is blunt and is provided with 

 three lips ; the tail of the female 

 is long and attenuated ; the vulva 



Fig. 40— Oxyuris Cur- . . ^ j • ^i ^ • ^i • j r 



vuLA (Female). ^^ locatcd m the anterior third of 



a, Cephalic extremity, the body. The male is provided 



b, Caudal extremity. . , -.. , , , , 



With a rudimentary caudal pouch 

 and one spicula; the posterior extremity is blunt. 

 The male is from one-half to three-fourths inch in 

 length ; the female is from one to one and one-half 

 inches in length ; the female is oviparous. 



Animals Infested. — The horse, the ass and the mule. 



Parts Infested. — Throughout the length of the large 

 intestine and the rectum. 



Co7iditio7i Produced. — Their presence in large num- 

 bers causes considerable irritation, which results in 

 ':. catarrhal state. After evacuation of the bowels 

 there is noted a small quantity of thick, whitish fluid 

 around the anus (the product of catarrh) which dries 



