PAPERS ON BIOLOGY AND AGRICULTURE 201 



sis occurred only below five meters. The list of the geu 

 era at dift'erent depths is given, together with the number 

 of individuals. 



A — From the surface to 5 meters. 



Arrhenurus manubriator Mar., 10. 



Arrhenurus scutulatus Mar., 5. 



Arrhenurus fern, unidentified, 16. 



Oxus, 1. 



Frontipoda americana Mar., 2. 



Lebertia. 72. 



Torrenticola, 50. 



Koenikea concava Wol., 17. 



Neumania, 19. 



Fiona, 13. 



Unionicola, 1. 



Limnesia, about 50. 



Sporadoporus, 11. 



B — Fro7n 5 meters to 10 meters. 



Arrhenurus manubriator Mar., 3. 

 Arrhenurus scutulatus Mar., 2. 

 Arrhenurus fern, unidentified, 9. 

 Koenikea concave Wol., 7. 

 Mideopsis, 5. 

 Xeumania, 4. 

 Fiona, 5. 

 Limnesia, 36. 

 Fionopsis, 1. 



Frorn 10 meters to 29 meters. 



Arrhenurus americanus Mar., 1. 

 Mideopsis, 2. 

 Neumania. 2. 

 Fiona, 1. 

 Limnesia. 1. 



