172 Dall — A New Bivalve from Louer California. 



Near the South Coronado L-^land, in three fathoms, collected by Dr. 

 Fred Baker, after whom it is named.. Types, U. S. Nat. Mus. No. 220,0!)!». 

 Cotypes in Baker and Cooke collections. 



This genus differs from the Leptonacea by haviufj the internal resilium 

 behind the cardinals as in the Astartacea, to which group it probably 

 belongs. In the structure of the hinge its nearest neighbor is the genus 

 Cuna Hedley, Ijut the latter is sufficiently different in detail to require no 

 special comparison. 



