180 



TEXTBOOK OP ZOOLOGY 



to twelve inches. Males are always more slender and have a curled 

 tail instead of the blunt tail of the female. The mouth is guarded 

 by three lips, two in lateroventral positions and one dorsal. These 

 lips have small papillae on their surfaces, two on the dorsal and 



Fig. 90.— Male and female Ascaris or eel-worm. 



one on each of the ventral. The shape of the body is generally 

 cylindrical with tapering ends. The smooth surface is marked by 

 four longitudinal lines, two lateral, one dorsal, and one ventral. 

 The genital pore in the female is located on the ventral midline 

 approximate!}^ one-third of the length of the body from the anterior 



