NO. 2 DEICHMANN : HOLOTHURIOIDEA ; PART II, ASPIDOCHIROTA 255 



of the Mexican coast to Isabel Island, designated as Mexico; and the 

 northern part divided into the Gulf of California and the West coast of 

 Lower California, including Guadalupe Island. 



The species are arranged in the same order as they appear in this 

 paper. 



The region explored is a fairly natural province with the fauna most 

 richly developed in the sheltered Gulf of California and in the Archi- 

 pelago of the Galapagos Islands, and dropping off sharply southwards 

 toward Peru and northward on the exposed western shore of Lower 

 California. 



