246 ALLAN' HAXCOCK PACIFIC EXPEDITION'S VOL. 20 



PLATE 15 



Fig. 24. Lutiarca 'Vcspcrtina (Morch) 1861. Off Punta Peqiiena, Baja 

 California, a. Outside of left valve, b. Inside of the same. 

 Length, 17.2 mm. 



Fig. 25. Lunarca sp. Panama, a. Outside of left valve, h. Inside 

 of the same. Length, 53 mm. 



Fig. 26. Lunarca sp. Isla Marchena, Oalapagos Islands. Outside 

 of right valve. Length, 45.7 mm. 



Fig. 27. Anadara (Cunearca) acquatoiialis (Orbigny) 1846. Off 

 San Jose, Ciuatemala. a. Dorsal view of young speci- 

 men, b. Outside of right valve, both valves together, c. 

 Outside of left valve. Length, 14 mm. 



