XI, D, 4 Seale: Shells of Mindanao and Sulu 263 



names; the top, or trochus, shell is shaped like a boys' top, 

 and the turban, or green snail, shell is turban-shaped and much 

 larger than the top shell. 



There are many places in Sulu waters where these shells are 

 found in abundance. Davao Gulf, the east coast of Mindanao, 

 Tawi Tawi, and Sitanki are well-known fisheries. Wherever 

 there is a good reef or a shore with large rocks, one or both 

 of these shells can usually be secured either by wading along the 

 reef or by naked diving in water of from 1 to 4 fathoms. 



The fishermen use these animals for food, and as a result many 

 of the shells are spoiled either by the dry heat or by the hot 

 water, which are employed to extract the animal from its shell. 

 The shells should not be heated, but should be buried in sand for 

 a month and then washed in the sea. Shells cleaned in this 

 way retain their luster and bring the highest price. 



HABITS AND LIFE HISTORY 



Both the trochus and the turbo are shallow-water shells and 

 are capable of moving about for a considerable distance. Their 

 food consists chiefly of sea moss and other vegetable matter. 



The animal reaches maturity in three years. The shell of an 

 adult trochus is about 9 centimeters across the base. An adult 

 turbo is 10 centimeters in diameter on its bottom surface. Very 

 little is known about the early stages of growth of either of 

 these important species. No serious attempt has ever been made 

 to cultivate them artificially, but I have kept them alive in an 

 aquarium for three months. It is possible that both shells could 

 be profitably cultivated provided that a sufficiently confined 

 space with a good food supply could be found. Because of the 

 increasing value of these shells, experiments in actual cultiva- 

 tion would be a most practical matter. 



VALUE OP THE SHELLS 



Trochus shells at the present time are valued at 28 pesos a picul 

 (63.25 kilograms) ; in 1909 the shells were valued at from 9 to 10 

 pesos a picul. 



During 1913, 253,395 kilograms of trochus shells, valued at 

 103,125 pesos, were exported from the Department of Mindanao 

 and Sulu, and during January, February, March, and April, 

 1914, 85,299 kilograms, valued at 32,969 pesos, were exported. 



The turban, or green snail, shell is valued at 26 pesos per 

 picul. During 1913, 65,035 kilograms, valued at 21,860 pesos, 

 were exported from Jolo and Zamboanga. During the first 

 four months of 1914, 7,778 kilograms, valued at 3,127 pesos. 



