new Siamese Nematode. 



411 



rest more vciitially. The spicules (figs. 3-5, S.) are equal 

 in leiigtii. They are wide dorso-ventrall}', sickle-shapetl, 

 with a finely striated surface, aud each ))resents much the 

 appearance o£ having a smaller tubular spicule enclosed 

 within it. There is an accessory piece (figs. 3-5, A. P.), 

 granular in appearance, and with a median ])rojectiou which 

 lies between the spicules near the cloacal opening. 



Fig. 3. 



Falcaustra sia7nensis. Caudal end of male, lateral view. 



A. P., accessory piece; CI., cloaca; I).E/., ejaculatory duct; Int., in- 

 testine; It., retractor muscle of spicule; 6'., left spicule; Su., 

 sucker-like organs; V.S., vesicula seminalis; 1-11, papillae. 



The female genital organs are similar in arrangement to 

 those of i'\/a/ca/a. The vagina runs forward and dorsally 

 for a distance of about 2 inm. from the vulva, gradually 

 expanding into a thick-walled muscular cliaiuber with a 

 maximum diameter of 0'45 mm. It then gives off two 

 opposed uteri. The anterior uterus rinis forward to a point 

 about 3 mm. from the junction of oesophagus and intestino, 



