92 THE NAUTILUS. 



In his checklist Dall merely states that it is found on the 

 oyster beds of the Bay ( Checklist of Recent Bivalve Mollusks of the 

 N. W. Coast, p. 18, 1916). 



Packard ( Univ. of Calif. Publ. Zool., Vol. 14, No. 2, p. 257, 

 1918) states in his report on the mollusca obtained by the U. S. 

 Bureau of Fisheries Survey of San Francisco Bay that, "Al- 

 though it was not taken by the Survey it is reported to occur 

 within the lower division of the Bay in sufficient numbers to be 

 marketed occasionally." 



The above is a review of all of the published records of the 

 species on the west coast which are known to the writer. Mrs. 

 Ida S. Oldroyd tells me she received specimens some years ago 

 collected by Fred L. Button at Alameda. Henry Hemphill 

 made wonderful discoveries during his extensive collecting on 

 the eastern side of the Bay, among other things, the sand clam, 

 My a arenaria, but his collection does not contain a specimen of 

 the plicated mussel from any west-coast locality. So it may be 

 inferred that he did not find it. 



Its extensive spread in the bay region however cannot be 

 doubted. Through Mr. R. A. Coleman the California Academy 

 of Sciences recently received 18 beautiful specimens of this 

 mussel. They were taken at Bay Farm Island about one mile 

 south of Alameda on the eastern side of the Bay. They were 

 found living on the mud flats in very considerable numbers at- 

 tached to the roots of Spartina stricta maritima, determined by 

 Miss Alice Eastwood, locally known as wild rice. It is said to 

 be occasionally brought into the markets from this locality. 



Mr. Coleman states that the mussels were delicious eating. 

 Many of the shells are over a hundred millimeters long and as 

 much as fifty millimeters wide. The epidermis has a very high 

 polish and the umbones have been only slightly eroded, in 

 many cases none at all. 



Those persons anxious to learn how long it takes to develop 

 a variety, subspecies or species may well keep watch of Modiolus 

 demissus. 



