338 



THE ZOOLOGIST. 



vestibule, and if there be any circumoral papillae they are too 

 minute to observe. The oesophagus is a delicate tube of uniform 

 thickness '01 mm., measuring 0*65 mm. in length. Its wall shows 

 faint transverse striae due to muscular fibres. At O'l mm. from the 

 mouth the oesophagus is crossed by the nerve-ring. The chyle 

 intestine, with a thickness almost double that of the oesophagus, 

 passes along the remaining length of the body to open at the 

 anus 0'05 mm. from the tip of the tail. 



The testicular tube shows many changes in diameter in its 

 long wavy course from anal aperture to its free blind end at 

 0*45 mm. from the anterior extremity of the body. Passing 

 forwards from the cloaca it gradually dilates to attain a width 

 of 0*1 mm. at 0*85 mm. therefrom. Suddenly constricting to 

 0'03 mm., it proceeds forwards as a narrow tubj for 0*4 mm. A 

 sharp kink occurs, and the tube soon widens to 0'05 mm. This 

 diameter is maintained for 3 mm. along a slightly tortuous 

 course. The tube now almost imperceptibly narrows to 0*02 mm., 

 and remains of this thickness until within 0'45 mm. of the mouth, 

 where the testis then curves upon itself to end in a small round 

 knob. 



The spicules are two in number, and of almost equal size 

 and shape. They are short and thick, with bent tips, and 

 measure 0*09 mm. The genital papillae were represented by 

 small cuticular knobs not at all easy to determine. One pair of 

 such papillae immediately in front of the anus and a second pair 

 almost at the tip of the tail were seen. Immediately behind the 

 anus there were indications of a third pair, but their existence is 

 doubtful. 



Description of the Female Worm. 



Total length about 12 mm., greatest breadth 0'3 mm., both 

 ends are bluntly pointed, the anterior tapering more gradually 

 than the posterior. The truncate anterior extremity measures 

 0*05 mm. in diameter ; this increases at the nerve-ring to 0*1 mm., 

 and at the vaginal opening, 0*4 mm. from the mouth, to 0'15 mm. 

 At 0*9 mm. the body has a breadth of 0*2 mm., and then slowly 

 increases until the middle of the body, where the maximum 

 diameter of 0*3 mm. is attained. For 3 mm. — i. e. to the level 

 of the junction of uterus with ovary — this thickness remains 

 unchanged, but thereafter it decreases ; at 1 mm. from the tail it 



