1908] 



Davis. Life-history of Dolichoglossus. 



197 



swift currents and disturbing waves. It is in such places that 

 fine, black mud, rich in organic matter, occurs. The animal is 

 never found in even moderately clean sand. 



The black-mud areas are associated with level surfaces which 

 are uncovered at low tide, with freedom from wave action, and 



MAP OF PORTION OF SAX DIEGO BAY. 



1. Entrance to San Diego Bay. 



2. Point Loma. 



3. North Island. 



4. Spanish Bight. 



5. Whaler's Bight. 



6. Coronado. 



8. Government breakwater. 



Heavy black shading in 4 and 5 indicates area of distribution of D. 

 pusillus. 



Region indicated by fine dots uncovered at low tide. 

 Region indicated by large dots covered at high tide. 



with marginal plant growth, part of which is submerged at very 

 high tides. Whaler's Bight and Spanish Bight of San Diego Bay 

 are typical illustrations of just such conditions. The map 

 (p. 197) is part of the San Diego Bay including the above bights. 

 A reference to this map will indicate to what extent these con- 

 ditions obtain in the area of distribution of D. pusillus. 



