280 SEALE. 



FRESH-WATER MOLLUSKS. 



The suso, black river-snail (Plate II, fig. 16), and the cohol, 

 green river-snail (Plate II, fig. 17), are apparently the only two 

 fresh-water mollusks (except Anodonta tenius) sold in the local 

 markets; however, these are quite abundant and sell for about 

 6 centavos per kilogram. 



In addition to the shells named, there are other species of 

 mollusks which are only occasionally found in the Manila 

 market, but which are of considerable importance as food in 

 other islands of the Archipelago, such as the various species 

 of Murex (Muricidse), tritons (Tritonidse), spindle shells (Tus- 

 cidse), volutes (Volutidse), olives (Olividse), cones (Conidae), 

 helmet shells (Cassididse), turbin shells (Turbanidae), top shells 

 (Trochidse), and abolons (Haliotidse). A complete list of these 

 species together with an account of their habits, abundance, 

 times of breeding, methods of reproduction, and notes regard- 

 ing the possibilities of their culture would be a most desirable 

 and useful work. 



