Plate 12 

 Fig. 1. Macotna nasitta. Mono Ba\-. Natural size. Exterior right valve. 



Fig. 2. MacoiiKi n((sii1a. same specimen as Fig. 1. Dorsal view. Note tliat the 

 siphonate end is bent toward the right. 



Fig. 3. Macouut secta Conrad : White sand clam. Morro Bay. Natural size. 

 Exterior right valve. 



Fig. 4. MacoiiKi secta, same specimen as Fig. .3. Dorsal view. Compare with 

 Mdcoma nastita. 



