12Q s. GOTO. 



(riüNfjtildris I have not l)een able to observe the vagina, since I had 

 only a single specimen of tliis species ; but its presence is scarcely to 

 be doubted. 



In HcxaciijJc also, the Nagina opens to the exterior (jn the dorsal 

 side of the body in the median line, a short distance behind the com- 

 mon genital pore on the ventral side (PI. XIII, ügs. 1 & 4; V\. XII, 

 fig. (i); and its internal surface is armed with numerous chitinous, 

 conical teeth similar to those of Axinc (PL XII, tig. (J ; PL XIV, 

 tig. o). The connective tissue annind it presents a very ditferent aspect 

 from that of the remaining [)arts of the body, and is exceedingly com- 

 [>act and refractiNc. It is somewhat yellowish in the fresh state, and 

 remains totally unstained with carmin or haemaioxylin. In tact it is 

 of the same nature as the tissue that sui'rounds the vagina in Axinc 

 and the terminal |)ortion of the vas deferens in Microfijle irliculaia and 

 Onchocoiijlc ; Ijut it is ïnr more compact, so that it appears as if it were 

 somewhat chitinous. In the genus under consideration the vagina is 

 surnjunded by numerous, circular nuiscular hljres; moreover from the 

 chitinous cuticle that lines its cavity numerous muscidar tibres take 

 rise and radiating in all directions and ramifying each int<j a 

 number of filrres. are at last inserted into the investing memljrane 

 of the body (PL XIV, fig. o). These muscular tibres are evidently 

 the rclnicloirs vatj'mae. The vagina soon divides into two cantds. the 

 canah's ccKjiiialcs^ whic-h, as in the cases already described, jrrocced on 

 the inner side of, and parallel to, the trunks of the intestine, and open 

 into the paired yolk-ducts. In accordance with the asynmietry in 

 this genus of the yolk-ducts of the tw(j sides, alreiidy mentioned, the 

 vaginal canal of the left side is longer than that of the right (PL XIII, 

 figs. 1 & 4; PL XIV, tigs. 1 Oc 7). 



From the above description the paired origin of the vagina in 

 Microcolijle. Axine, and Hcxucolijh is, I believe, beyond question. 



