2 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.66 



size, and especially in tlie numerous spiral striae. The two may, 

 however, be but variations of the same species. It is hardly possible 

 to tell to just what extent the process of digestion in the bird's 

 stomach has affected the color of the shells. That digestion had not 

 progressed very far is indicated by the generally fine condition of 

 the periostracum and the clear, clean, enamel-like appearance of the 

 white columella and callus. 



CHILINA CASTANEA, new species. 



Plate 1, fig. 5. 



Shell ovoid, moderately thin; suture very narrowly channeled; 

 entire surface of the shell obscurely, spirally striated, the striae more 

 pronounced just below the suture; axial growth lines numerous, vary- 

 ing from fine striae to rather coarse riblets; last whorl malleated, 

 especially behind the outer lip. General color a rich, glossy chest- 

 nut, with several faint spiral bands made up of arrow-head markings 

 of darker color. The aperture is about three-fourths of the length 

 the shell would have were not a small portion of the apex eroded. 

 Columella not very broad, its edges slightly arcuate, and bearing a 

 moderately strong, transverse tooth on the inner edge of its upper 

 end. Parietal wall covered with a callus and bearing a small trans- 

 verse tooth at its middle portion. Columella and teeth white. Outer 

 lip simple, slightly sinuous. Interior of aperture whitish with a livid 

 cast and with four fairly distinct spiral bands of purplish color. 



The type. Cat. No. 359911, U.S.N.M., measures: Length, 18.5 

 mm. ; diameter, 11.5 mm. ; length of aperture, 14 mm. It and two 

 other specimens. Cat. No. 359912, U.S.N.M., come from Rio Corco- 

 vado. Province of Chubut, Argentina, and were received from Mrs. 

 T. S. Oldroyd. The label with the specimens states that this river 

 is in the Pacific drainage. Three other specimens from the same 

 locality were returned to Mrs. Oldroyd. 



The rich glossy chestnut color serves to distinguish this species. 



CHILINA PARCHAPPII MINOR, new subspecies. 



Plate 1, fig. 7. 



Similar to the typical species except that it is smaller, the tooth 

 is very small, and within the aperture there are four interrupted 

 purplish revolving bands corresponding to similar bands on the 

 exterior. 



The type, Cat. No. 360164, U.S.N.M., measures: Length, 18 mm.; 

 diameter, 9 mm. ; length of aperture, 12 mm. It comes from the Mar 

 del Plata, Argentina. Cat. No. 348256, U.S.N.M., includes three 



