STEONGYLUS SUB^TlLIS IN JAPAN. 159 



seem to me su&icieiifc to prove the identity of the worm with 

 Stronyylus suhtills of Looss. Not only am I unable to add any new 

 matter to what became known through Looss' work but several im- 

 portant points touched upon by that author had either escaped my 

 attention or could not be made out in my specimens. 



I must say I have no observation whatever on the nerves, the 

 excretory organs, the longitudinal lines, the musculature and the 

 oesophageal glands. 



A male individual measured by me was 4.5 mm. long. It was 0.07 

 mm. broad just in front of the tvvo-lobed bursa, which, as measured in a 

 lateral view of the worm, was about 0.13 mm. broad. Anteriorly the body 

 narrowed like a whip until at the extreme head-end it was no broader than 

 O.Ol mm. Not only in size and general shaps does my sketch of a male 

 specimen agree with Strongyliis suhtilis but also in the arrangements 

 of the alimentary canal and of the internal genital organ ; in the posi- 

 tion, size, number and peculiar shape of the spiculae ; in the fine an- 

 nulation of the cuticula ; and in the general structure of the bursa 

 copulatrix. One thing which I do not find mentioned by Looss and yet 

 I believe to have been distinctly seen by myself, is a pair of small and 

 low fin-like expansion of the skin situated close behind the anterior end. 

 I have noticed it only on a male specimen but believe it to be present 

 also on the other sex. 



A female specimen measured by me was 5.4 mm. long and 0.07 

 mm. thick at about the position of the vaginal opening. Ogata gave 

 5-6 mm. as the length of females. These measurements fall slightly 

 below those given by Looss for Strongijlus suhtilis of the same sex 

 (5.6-7 mm. length); but the difference can not be of much importance 

 in view of the fact that the greatest length given by Ogata exceeds the 

 minimum length as given by Looss. With respect to the external 

 configuration of females as well as of their digestive apparatus and genital 

 organs, it is needless to enter into descriptions as my observations 

 essentially agree with the results of Looss both in the arrangement and 

 in the relative proportions of parts. The peculiar " Verschlussapparat " 



