NO. 5 INTERMEDIATE HOSTS OF ASIATIC BLOOD FI.UKE BARTSCH 3 



It is deemed wise here to give reasons why a clean hill of health is 

 hestowed upon them. 



The most important genus, as far as Asiatic schistosomiasis is 

 concerned, is Kalayama, which ranges from southern Japan through 

 Formosa, to Canton, China. 



In China hy far the most important intermediate hosts are the 

 various species of Oncomclania, all of which, whether technically 

 demonstrated as intermediate hosts or not, should he looked upon 

 as a potential menace. 



The last genus, Schisiosoiiiopliora, estal)lished in this paper, in- 

 cludes the newly demonstrated host of Schisfosoina in the southern 

 Philippines ; one species not yet a demonstrated host is found in the 

 Island of Honshu, Japan. 



1 will now give a series of keys which I helieve will prove helpful 

 to students in the identification of these genera. 



KEY TO THE RADULAE OF THE GENERA OF THE, INTERMEDIATE HOSTS 

 OF SCHISTOSOMA JAI'ONICUM 



Rachidian tooth 3-cusped in adults ' 



Basal denticles 3-3 Katayama. 



Basal denticles 2-2 Oncomclania. 



Rachidian tooth 5-cusped in adults ' 



Basal denticles 2-2 Scliistosonwpliora. 



Basal denticles 4-4 Blanfordia.'^ 



KEY TO THE OPERCULA OF THE GENERA OF THE INTERMEDIATE 

 HOSTS OF SCHISTOSOMA JAPONICUM 



Whorls 1.5 Scliistosonwpliora. 



Whorls 2.2 



Nucleus very excentric Oncomclania. 



Nucleus not very excentric Blanfordia. 



Whorls 2)~ Katayama. 



Unfortunately, the characters of the shells are not as clear cut 

 as the radula and opercula, and their placement in a key would he 

 rather involved. Suffice it to say here that Oncomelania, always, as 

 far as we know, has the shell axially ribbed ; Katayama in Japan and 

 China has the shell elongate-conic, but in the Formosan species it is 

 ovate, thus resembling Blanfordia and Schistosomophora. The Blan- 

 fordias are larger than the Schistosomophoras, excepting Blanfordia 

 integra, which is almost as small. 



' In very young mollusks or unworn parts of the radula a slight outer third 

 cusp may be present on each side of the central tooth. 



^ No species of the genus Blanfordia' as here limited has st) far been implicated 

 as intermediate host of Schistosoma japonicnm. 



