103 



behandeln und auf Grund dieser Sammlungen Beiträge zur Kenntnis 

 älterer und neuerer Arten geben wird. In zahlreichen Familien und 

 Gattungen der Decapoden ist die Artenkenntnis auch heute noch eine 

 durchaus provisorische, und jede einigermaßen umfangreiche Collec- 

 tion vermag hierzu werthvolles Material beizubringen. 



3. On the Connecting Canal between the Oviduct and the Intestine in some 

 Monogenetic Trematodes. 



(Preliminary communication.) 

 By S. Goto, 

 Zoological Institute, Imperial University, Tokyo, Japan. 



eingeg. 4. März 1891. 



The presence of a peculiar canal connecting the oviduct with the 

 intestine in some ectoparasitic Trematodes was first observed by Ij ima 1 ; 

 but his statements have, so far as I know, not yet met with corrobo- 

 ration except by Ramsay Wright and Macallum [Sphyr anitra) 2 . One 

 writer has even roundly denied the truth of Ijima's statements. For 

 some time past I have occupied myself with the anatomy of our ecto- 

 parasitic Trematodes, and have been able to confirm I j ima' s statement 

 about the presence of a peculiar canal by which the oviduct and the 

 intestine are put in direct communication with each other. I have 

 carefully traced the course of the canal in question in Axine (2 sp. , 

 Microcotyle (8 sp.), Octobothrium (2 sp.) , and Diplozoon (1 sp.) and 

 have invariably found it to open into the intestine by one of its ends. 

 Zell er 3 states that in Diplozoon the vas deferens of one individual 

 opens into the Laurer's canal of the other; but I have not found any 

 such relation to exist. His Laurer's canal is evidently the connecting 

 canal above spoken of; and the vas deferens of one individual 

 distinctly opens into the yolk-duct of the other. This point 

 has seemed to me so interesting that I have traced the course of the 

 vas deferens as well as of the connecting canal in a number of serial 

 sections, and could always, in good sections, demonstrate the truth of 

 the above statement. 



It would be interesting to make out the homology of this canal- 

 whether a homologous canal exists in all monogenetic Trematodes and 

 whether it is homologous with the Laurer's canal of the Distomes. 

 This point I hope to be able to elucidate in some future paper. 



1 This Anzeiger. 7. Jhg. p. 635. 



2 Journal of Morphology. Vol. 1. p. 41. 



3 Ztschr. f. w. Zool. 46. Bd. p. 237. 



