THE NAUTILUS. 



VOL. XXVIII. OCTOBER, 1914. No. 5 



A NEW SPECIES OF LEPTACHATINA. 



BY H. A. PILSBRY. 



LEPTACHATINA COOKEI n. sp. 



The shell is perforate, ovate-conic, weakly marked with 

 growth-lines, or nearly smooth, and glossy in the best pre- 

 served specimens. Apex small, obtuse, the spire straightly 

 conic above, convex below ; the last whorl more or less notice- 

 ably compressed, more flattened than the penultimate whorl; 

 the base is convex, compressed around the axial crevice. 

 Whorls 6y 2 slowly enlarging the penultimate somewhat con- 

 vex, those above nearly flat. The suture is superficial; in 

 the last third of a whorl it ascends slightly and at the aperture 

 it is rather abruptly, arcuately deflexed. The aperture is 

 oblique, ovate, contracted ; outer lip obtuse ; columellar lip 

 reflected, thickened on the face, and appressed above the 

 narrow perforation, continuous with a callous cord which 

 bounds the rather thick parietal callus, and terminates in an 

 enlargement or tubercle which is separated from the termin- 

 ation of the outer lip by a narrow groove or posterior com- 

 missure of the aperture. The columellar lamella is thin, 

 broad and subhorizoutal, outwardly emerging to the edge of 

 the columella. 



