304 ASAJIKO OKA; ON SOME NEW 



The Family Herpohdellidce counts, thus, at least six genera, 

 Herpohdella, Dina, Trocheta, Ctjclohdella, lAiinhricohdella, and Orohdella. 

 To include all these genera, the above diagnosis must he altered in 

 regard to the number of eyes and to the habit. It will run as follows; — 

 Hirudinea, uitliout jjwhoscis, without jaws ; eijes in less than 5 pairs or 

 wliollij irantiiKj ; rings withont external inarl'intj that distinguishes some 

 from tlte rest ; number of rings in a complete somite 5—11. The other 

 minute chfiracters are important only in determining the genera. 



The position which Orohdella occupies in the order Hirudinea is, 

 according to the results of my investigations, that shown in the adjoin- 

 ing synoptical table. 



Ordo. Hirudinea 



a. Subordo RlnjnchoJtdellœ 

 h. Subordo Arlnjncliohdellœ 



1. Fam. Gnathohdellidœ 



Aquatic: gen. Hirudo, Hœntopis, Limnatis, &c. 

 Terrestr. : gen. Hœmadipsa, Xerohdella, Meso- 

 hdella. 



2. Fam. Herpohdellidce 



Aquatic: gen. Herpohdella, Dina, Trocheta 

 Terrestr. : gen. Gylicohdella, Liuidiricohdella, 

 Orohdella. 



