1902.] NATURAL SCIENCES OF PHILADELPHIA. 707 



mens darker colored and larger, forming the variety named Lazaria 

 californica by Deshayes in 1852. The ribbing is relatively 

 stronger in the young, and in the adult is often obsolete anteriorly. 

 The animals adhere by a strong byssus and, when crowded, the 

 anterior end is arcuate and attenuated ; but when growing freely 

 this is much less marked. A specimen has been figured by Reeve 

 for C. pedunculus Brug. 

 Cardita (Carditamera) radiata Sowerby, 1852. 



Punta Arenas, Costa Rica, to Panama Bay and Guayaquil, in 6 

 to 12 fathoms. 



Very similar to C. affinis, but with a very different hinge and 

 more checkered coloration. The lunule is also larger and wider 

 than in that species. C. arcella Valenciennes, 1846, figured on 

 the plates of the Voyage of the Venus, but never described, may, 

 perhaps, have been intended for this species. 

 Cardita (Carditamera) subquadrata Carpenter, 1865. 



Skidegate Channel, Queen Charlotte Islands, in 20 fathoms, 

 Newcombe ; Straits of Fuca and southward to the Santa Barbara 

 Channel and Todos Santos Bay, Lower California. 



Small, solid, subquadrate, speckled with brown. The soft parts 

 are yellow with brown spots on the mantle edge, 

 Cardita (Glans) sulcosa Dall, 1902. 



Panama Bay, in 18 to 30 fathoms, sand; U. S. Fish Commission 

 steamer " Albatross." 



Small, quadrate, variegated in color, with a deep sulcus in the 

 posterior end which emarginates the border of the shell. 

 Cardita (Glans) naviformis Reeve, 1843. 



Valparaiso, Chile, in 25 fathoms, sandy mud, Cuming. 



Small, rectangular, very inequilateral, the beaks almost terminal, 

 the posterior end squarely truncate, with 12-15 scaly ribs. 

 Venericardia crassicostata Sowerby, 1825. 



Gulf of California and southward to the Galapagos Islands. 



This fine, variably colored species is Cardita jiammea Michelin, 

 1830, C. tumida and varia of Broderip, 1832. The differences are 

 merely of color, the form being very uniform. The Cardita 

 crassicosta of Lamarck is a typical Cardita, but if the name given 

 by Sowerby in the Tankervilie catalogue be thought too close, 

 Michelin' s name must be adopted. 



