34 THE NAUTILUS. 



dred species, hut one sinistral individual was found, of the species 

 A. cornea Wood. It is a clearly defined Ampullaria, and could not 

 be confounded with the genus Lanistes. Jennie E. Letson. 



HELICINA RABEI, n. sp. Shell lenticular, acutely carinated low- 

 conic above ; yellowish- or fleshy-white or red variously banded and 

 figured ; surface finely sulcate spirally. Whorls 85, flat above, the 

 last convex below the acute peripheral keel. Aperture subtriangu- 

 lar, oblique, dark red within, at least in part; peristome well ex- 

 panded, white ; axial callous heavy, rugose, varying from dark 

 reddish-brown to translucent white in color. Alt. 6'3, greatest diarn. 

 11, lesser 8 - 7 mm. Another specimen measures, alt. 5'2, diameters 

 9 and 7'5 mm. Pelew Is. (Dr. Rabe). This acutely keeled and 

 spirally lirate species is remarkably variable in coloration. Types, 

 no. 68,854 coll. A. N. S. P., presented by Mr. John Ford. H. A. 

 Pilsbry. 



RECENT PUBLICATIONS RECEIVED. 



Professor Wm. H. Ball's Report on the Mollusks collected by the 

 International Boundary Commission of the United States and Mex- 

 ico, 1892-1894 (Proc. U. S. Nat.Mus., 1896, issued in 1897), is one 

 of the most important documents yet published upon the inland 

 mollusk fauna of the southwest. It treats of a region rarely visited 

 by snail collectors, and consequently but little known, and places 

 the conchology of the region on a solid basis. The region north of 

 Mexico, between the Rio Grande and the Colorado, seems to be a 

 prolongation northward of the fauna of the mountains of northern 

 Mexico, rather than a southern extension of that of the Great Basin 

 west of the Rocky Mountains. It presents features due to contri- 

 butions from the Californian and Mexican regions, the latter pre- 

 dominating, with a few stragglers from the north. The plains are 

 almost uniformly arid and frequently alkaline, and nearly all the 

 Pulmonates were collected at the upper levels of the various mount- 

 ain ranges near the boundary. Epiphragmophora extends into the 

 region, being represented in Arizona and New Mexico by four spe- 

 cies, of which two, arizonensis and hachitana are new. The Poly- 

 gyra levettei groups proves to be prolific in species, five, of which 

 four are described by Dall, being found. The classification of Holo- 

 -spira proposed in the last volume of THE NAUTILUS is fully set forth 



