300 



ASAJIRO OKA; ON SOME NEW 



very soft body attenuated toward the head, with a very well developed 

 acetabulum. The other liaving large month and hunting after earth- 

 worms has a long cylindrical body of nearly the same thickness through- 

 out, and not so soft and distensible as that of former. The acetabu- 

 lum is comparatively of little use in moving under mosses and is 

 consequently on the w^ay to disappear. The most important dif- 

 ference from the morphological point of view is in the number of rings 

 that make one complete somite, which is 5 in Hœmadipsa and 4, 6, or 

 8 in OrohdeUa. 



The two forms of land-leeches from Trinidad reported by Kennel 

 (1886) seem to be the most nearly allied to OrohdeUa. They agree in 

 their mode of life, which brings with it resemblance in the external 

 form of the body. In their internal anatomy too, they present many 

 points of agreement. How far these land leeches resemble each other 

 and how far they diifer may be summed up as in the following table : 



Body: 



No. of rings : 



No. of rings in 

 a somite : 



Eyes: 



Jaws : 



Acetabulum : 



Length of the 

 œsophagus : 



Dorsal blood 

 vessel : 



No. of round 

 blood-sinuses 

 in a somite : 



Nephridial 

 funnel : 



Testes : 



No. of intesti- 

 nal blind-sacs: 



