450 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.49. 



KENNERLYIA PATAGONICA, new species. 



Shell bearing a marked resemblance to the K. hilirata of the Cahfor- 

 nia coast; white with a dehiscent grayish periostracum; hinge line 

 nearly straight, the posterior left dorsal margin sharply reflected out- 

 ward, with two sharp radial hnes below it; the surface of the disk 

 anteriorly has a few obscure hardly elevated radial hnes, with the 

 anterior area feebly marked and only shghtly interrupting the basal 

 margin, which is evenly rounded; posterior end truncate above but 

 hardly rostrate; right valve flat above, concave near the basal mar- 

 gin, with a few irregular radial impressed lines, and two grooves 

 above, corresponding to the hrae of the opposite valve; basal curve 

 meeting the anterior dorsal margin in a sharp angle; hinge very 

 feeble, teeth very short, and adductor scars very small. Length, 

 14.5; height, 8; diameter, 2; beaks behind anterior end, 3.5 mm. 



Distribution. — Type locahty, west coast of Patagonia in 61 fathoms, 

 mud; bottom temperature, 54° F. Cat. No. 96937, U.S.N.M. 



This Uttle species is surprismgly hke the northern one. The only 

 other one of the group yet found in the Patagonian region is a Pandora. 



Subgenus CLIDIOPHORA Carpenter, 1864. 

 CLIDIOPHORA CLAVICULATA Carpenter, 1855. 



Distribution. — From Scammon Lagoon, Lower California, to 

 Panama. Cat. No. 15931, U.S.N.M. 



Subgenus HETEROCLIDUS Dall, 1903. 

 HETEROCLIDUS PUNCTATUS Dall. 



Clidiophora punctata (Conrad, 1837) Carpenter, 1855. 



Distribution. — Clayoquot, Vancouver Island, British Columbia, 

 and south to the Gulf of Cahfornia. Cat. No. 15794, U.S.N.M. 



This species lacks the long posterior left lamina which is one of the 

 characteristics of the typical Clidiopliora. 



Subgenus COELODON Carpenter, 1864. 

 COELODON RADIANS, new species. 



Shell small, dehcate, white, arcuate behind the beaks, compressed, 

 with the anterior area defined by an impressed line but not inter- 

 rupting the basal margin; posterior dorsal margin flat, with one 

 sharp radial lira below its outer edge ; anterior dorsal margin straight, 

 short; surface of the valves smooth except for incremental Hnes, with 

 a pale straw colored periostracum; basal margin evenly arcuate; 

 right valve with three short diverging teeth, the central one shortest; 

 left valve with two rather short diverging laminae with a short deck 

 covering the angle at their junction, the resilium attached to the 

 anterior face of the posterior tooth and carrying a thin lithodesma. 



