382 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvi. 



This species is easih" distinguished by its fine close sculpture and 

 pale grayish color from either of the other American species of 

 Cytherea. The interior is pure white. 



CYTHEREA (VENTRICOLA) CALLIMORPHA, new species. 

 Plate XIII, fig. 6. 



Shell small, globose, covered with a thin yellowish periostracuni 

 over a white shell with a salmon-colored flush internallj^; beaks full, 

 23rominent, the apices turned forward; lunule cordate, circumscribed, 

 evenly striated; surface with about 27 primary concentric lamellfe 

 having a T-rail section, the flat interspaces having 6-8 extremely fine 

 low concentric threads, crossed by fine radial striation; escutcheon 

 limited by an obscure ridge, ending in a subangular projection of the 

 margin; in front of the ridge is a wide shallow radial depression; 

 hinge well developed; posterior right cardinal long, distant from the 

 others and bifid; middle right cardinal deeply bifid; anterior lateral 

 small, papilliform; interior surface polished,' with a salmon-colored 

 flush behind the beaks; pallial sinus small, sharply angular, ascending; 

 inner margins finely crenate. Length 16; height 14.5; diameter 12 mm. 



Station 272, in 76 fathoms, at Barbados, West Indies, United States 

 Coast Survey steamer Blale. Cat. No. 64292, U.S.N.M. 



The peculiar form of the primary lamellse renders them verv liable 

 to fracture, and if broken ofl' they leave no visible trace, and the sur- 

 face appears uniformly concentrically threaded, since the basal attach- 

 ment of the primaries is no wider than the normal width of the 

 secondary threads. 



CHIONE MAZYCKII, new species. 

 Plate XIII, fig. 2. 



Shell small, subrostrate, with low distant concentric lamella? crossing 

 flat radial ribs, those radials in front of the middle later becoming 

 double, while the ribs behind the middle remain single; all the ribs 

 are separated by subequal smooth interspaces except near the anterior 

 margin, where interstitial threads appear; the concentric lamellae 

 become laminate, especially on the right valve, near the posterior end; 

 lunule distinct, lanceolate, striated; escutclieon defined by a keel, 

 striated, the right half somewhat overlapping the other, painted with 

 brown streaks or entirely brown; disk white with pale-brown or rose- 

 colored radial l)ands and occasional darker-T)rown flecks; interior rose 

 color with white near the end and basal margins; hinge normal, with 

 a rose-colored ray lielow a very short ligament; pallial sinus very 

 small and ])lunt. inner margins crenulated. Length, 14.2; height, 11.2; 

 diameter, 8 nnn. 



Tt/2)e locality. — I'nited States Fish Commission station 2616, ofl' 



